Form 424B5

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and we are not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

Blackstone Mortgage Trust, Inc., a Maryland corporation, is a real estate finance company that originates and purchases senior loans collateralized by commercial properties in North America and Europe. We are externally managed and advised by BXMT Advisors L.L.C., a Delaware limited liability company, or our “Manager,” an affiliate of The Blackstone Group L.P., which we refer to as “Blackstone.” We conduct our operations as a real estate investment trust, or “REIT,” for U.S. federal income tax purposes. To assist us in qualifying as a REIT, among other purposes, stockholders generally will be restricted from owning more than 9.9% in value or number of shares, whichever is more restrictive, of the outstanding shares of our capital stock or of our class A common stock. In addition, our charter contains various other restrictions on the ownership and transfer of our class A common stock. See “Description of Capital Stock—Certain Provisions of Our Charter and Bylaws and of Maryland Law” in this prospectus supplement for a description of these restrictions.

We are offering 10,000,000 shares of our class A common stock. All of the shares of our class A common stock offered by this prospectus supplement are being sold by us. Our class A common stock is traded on the New York Stock Exchange, or “NYSE,” under the symbol “BXMT.” The last reported price of our class A common stock on the NYSE on May 29, 2015 was $30.22 per share.

Investing in our class A common stock involves risks. See “Risk Factors” beginning on page S-5 of this prospectus supplement and in the reports we file with the Securities and Exchange Commission pursuant to the Securities Exchange Act of 1934, as amended, incorporated by reference in this prospectus supplement or the accompanying prospectus, to read about factors you should consider before buying shares of our class A common stock.

None of the Securities and Exchange Commission, any state securities commission, or any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

The underwriters have agreed to purchase the shares of our class A common stock offered by this prospectus supplement from us at a price of $ per share, which will result in approximately $ million of total net proceeds to us before expenses payable by us. The underwriters may offer the shares of our class A common stock from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices. See “Underwriting.”

The underwriters will have the option to purchase within 30 days from the date of this prospectus supplement up to an additional 1,500,000 shares of our class A common stock from us.

We have agreed to reimburse the underwriters for certain expenses in connection with this offering. See “Underwriting.”

The underwriters expect to deliver the shares against payment in New York, New York on or about June , 2015 through the book-entry facilities of The Depository Trust Company.

You should rely only on the information contained in this prospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by us or information to which we have referred you, including any information incorporated by reference. We have not, and the underwriters have not, authorized any other person to provide you with additional information or information different from that contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus. We are not, and the underwriters are not, making an offer to sell shares of class A common stock in any jurisdiction where the offer or sale is not permitted.

You should assume that the information appearing in this prospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by us is accurate only as of their respective dates or on the date or dates which are specified in such documents, and that any information in documents that we have incorporated by reference is accurate only as of the date of such document incorporated by reference. Our business, financial condition, liquidity, results of operations and prospects may have changed since those dates.

This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering of class A common stock and also adds to and updates the information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part is the accompanying prospectus, which provides more general information about our class A common stock and other securities that do not pertain to this offering of class A common stock. To the extent that there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference that was filed with the Securities and Exchange Commission, or “SEC,” before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date (for example, a document incorporated by reference in this prospectus supplement or in the accompanying prospectus) the statement in the document having the later date modifies or supersedes the earlier statement. The information in this prospectus supplement may not contain all of the information that is important to you. You should read this entire prospectus supplement, the accompanying prospectus and the documents incorporated by reference carefully before deciding whether to invest in our class A common stock. See “Where You Can Find More Information” in this prospectus supplement and the accompanying prospectus.

Unless the context otherwise indicates, references in this prospectus supplement to the terms “company,” “we,” “us,” “our,” and “Blackstone Mortgage Trust” refer to Blackstone Mortgage Trust, Inc., a Maryland corporation, and its consolidated subsidiaries; “Manager” refers to BXMT Advisors L.L.C., a Delaware limited liability company, our external manager; and “Blackstone” refers to The Blackstone Group L.P., a Delaware limited partnership, and its subsidiaries.

This prospectus supplement and the accompanying prospectus, including information incorporated by reference herein and therein, as well as any other oral or written statements made in press releases or otherwise by us or on our behalf, may contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the “Securities Act,” and Section 21E of the Securities Exchange Act of 1934, as amended, or the “Exchange Act,” which involve certain known and unknown risks and uncertainties. Forward-looking statements predict or describe our future operations, business plans, business and investment strategies and portfolio management and the performance of our investments. These forward-looking statements are generally identified by their use of such terms and phrases as “intend,” “goal,” “estimate,” “expect,” “project,” “projections,” “plans,” “seeks,” “anticipates,” “should,” “could,” “may,” “designed to,” “foreseeable future,” “believe,” and “scheduled” and similar expressions. Our actual results or outcomes may differ materially from those anticipated. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date the statement was made. We assume no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Our actual results may differ significantly from any results expressed or implied by these forward-looking statements. Some, but not all, of the factors that might cause such a difference include, but are not limited to:

Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. We caution you not to place undue reliance on these forward-looking statements. All written and oral forward-looking statements attributable to us or persons acting on our behalf are qualified in their entirety by these cautionary statements. Moreover, unless we are required by law to update these statements, we will not necessarily update or revise any forward-looking statements included or incorporated by reference in this prospectus supplement and the accompanying prospectus after the date hereof, either to conform them to actual results or to changes in our expectations.

SUMMARY

This summary highlights certain information about us and the shares of our class A common stock being offered by this prospectus supplement and the accompanying prospectus. This summary is not complete and does not contain all of the information that you should consider prior to investing in our class A common stock. For a more complete understanding of our company, we encourage you to read this entire document, including the information incorporated by reference into this document and the other documents to which we have referred. Unless indicated otherwise, the information in this prospectus supplement assumes the underwriters do not exercise their option to purchase up to an additional 1,500,000 shares of our class A common stock.

Overview

Blackstone Mortgage Trust, Inc., a Maryland corporation, is a real estate finance company that originates and purchases senior loans collateralized by commercial properties in North America and Europe. Our business plan is to create the premier global commercial real estate lending platform and to originate, acquire and manage commercial real estate loans and securities and other commercial real estate-related debt instruments. While the commercial real estate debt markets are complex and continually evolving, we believe they offer compelling opportunities when approached with the institutional capabilities and expertise of our Manager, an affiliate of Blackstone, one of the world’s leading investment and advisory firms. Our investment objective is to preserve and protect our capital while producing attractive risk-adjusted returns primarily through dividends generated from current income on our portfolio.

Our investment strategy is to originate loans and invest in debt and related instruments supported by institutional quality commercial real estate in attractive locations. Through our Manager, we draw on Blackstone’s extensive real estate debt investment platform and its established sourcing, underwriting and structuring capabilities in order to execute our investment strategy. In addition, we have access to Blackstone’s extensive network and Blackstone’s substantial real estate and other investment holdings, which provide our Manager access to market data on a scale not available to many competitors.

Our Manager is a part of Blackstone’s alternative asset management business, which includes the management of private equity funds, real estate funds, REITs, funds of hedge funds, credit-focused funds, collateralized loan obligation vehicles, collateralized debt obligation vehicles, separately managed accounts and registered investment companies. Blackstone also provides various financial advisory services, including financial and strategic advisory, restructuring and reorganization advisory, capital markets and fund placement services. On October 10, 2014, Blackstone announced that its board of directors had approved a spin-off of its financial and strategic advisory, restructuring and reorganization advisory and its fund placement services business, which is expected to close in 2015.

Through its different businesses, Blackstone had total assets under management of approximately $310.5 billion as of March 31, 2015.

We made a tax election to be treated as a real estate investment trust, or “REIT,” for U.S. federal income tax purposes, effective January 1, 2003. We also operate our business in a manner that permits us to maintain our exclusion from regulation under the Investment Company Act of 1940, as amended, or the “Investment Company Act.”

Blackstone Mortgage Trust, Inc. was incorporated in Maryland in 1998. Our principal executive offices are located at 345 Park Avenue, 42nd Floor, New York, New York 10154, and our telephone number is (212) 655-0220. Our website address is www.bxmt.com. The information on, or otherwise accessible through, our website does not constitute a part of this prospectus supplement.

Recent Developments

Loan Portfolio Acquisition

As previously announced, on April 10, 2015, we entered into an agreement to acquire a $4.6 billion portfolio of commercial mortgage loans secured by properties located in North America and Europe, or the “Loan Portfolio,” from General Electric Capital Corporation and certain of its affiliates, or “GE Capital.” The Loan Portfolio acquisition is part of a larger $23 billion acquisition by affiliates of Blackstone and Wells Fargo Bank, National Association, or “Wells Fargo” of the majority of GE Capital’s global real estate debt and equity business, consisting of a portfolio of real-estate related assets, including properties, loans, mortgages and other interests. On June 1, 2015, we announced that we have completed the first two of several closing stages contemplated by the agreements governing the acquisition of the Loan Portfolio and have consummated the purchase of an aggregate of 28 commercial mortgage loans secured by properties located in the United States, or “Initial Loans”. The purchase price paid by us for the Initial Loans was approximately $1.0 billion in cash, and was funded using a combination of borrowings under the Wells Fargo facility (as defined below) and the proceeds of the equity offering we completed on April 17, 2015.

The acquisition of the remaining assets comprising the Loan Portfolio is expected to be substantially completed by the end of the second quarter of 2015. However, there can be no assurance that the closing of all or any portion of the remainder of the Loan Portfolio will occur. See Part II, Item 1A in our Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2015 for a discussion of certain risks related to the Loan Portfolio acquisition.

Secured Financing

On May 28, 2015, the Master Repurchase and Securities Contract between certain of our special purpose wholly-owned subsidiaries and Wells Fargo was amended to increase the facility amount to $833 million, as amended, “Wells Fargo facility.” The Wells Fargo facility was entered into in accordance with the previously announced commitment by Wells Fargo to provide for $4.0 billion of secured financing to be used by us to finance a portion of the purchase price of the Loan Portfolio. We used the funds currently available to us under the Wells Fargo facility to finance a portion of the purchase price for the closing of the Initial Loans. We anticipate that we will continue to amend or supplement the Wells Fargo facility to increase the facility amount as we complete the final stages of its acquisition of the Loan Portfolio. For further details regarding the Wells Fargo facility, see our Current Report on Form 8-K filed with the SEC on June 1, 2015.

Letter of Intent

On May 27, 2015, we entered into a letter of intent outlining the terms and conditions of our proposed purchase of a portfolio of eight commercial loan participation interests in the GE Capital loan portfolio totaling approximately $475 million. We expect the transaction will be consummated by the end of the second quarter of 2015, subject to entry into definitive documentation and satisfaction of customary closing conditions. However, there can be no assurance that we will enter into definitive documentation for or close the proposed transaction.

Recent Origination Activity

On June 1, 2015, we announced that in addition to closing the Initial Loans, during the second quarter ending June 30, 2015 for the period through June 1, 2015 we have also closed direct originations totaling approximately $1.1 billion, of which $590 million was financed through the syndication of non-consolidated senior interests. In addition, as of June 1, 2015, over $900 million of loans have agreed terms and are in the closing process.

The Offering

The following summary is provided solely for your convenience and is not intended to be complete. You should read the full text and more specific details contained elsewhere in this prospectus supplement and the accompanying prospectus.

Issuer

Blackstone Mortgage Trust, Inc.

Class A common stock offered by us

10,000,000 shares (plus up to an additional 1,500,000 shares of our class A common stock that we may issue and sell upon the exercise of the underwriters’ option to purchase additional shares of class A common stock)

Class A common stock outstanding after this offering (1)

91,731,236 shares (or 93,231,236 shares, if the underwriters’ exercise their option to purchase 1,500,000 additional shares of class A common stock in full)

Use of proceeds

We estimate that the net proceeds we will receive from this offering will be approximately $ million, after deducting estimated offering expenses payable by us of approximately $350,000 (or, if the underwriters exercise their option to purchase 1,500,000 additional shares of class A common stock in full, approximately $ million, after deducting estimated offering expenses payable by us of approximately $350,000). We plan to use substantially all of the net proceeds from this offering to originate and purchase additional commercial mortgage loans and other target assets and investments consistent with our investment strategies and investment guidelines. We may also use a portion of the net proceeds for working capital and other general corporate purposes. See “Use of Proceeds.”

Dividend policy

We intend to make regular quarterly distributions to holders of our class A common stock. U.S. federal income tax law generally requires that a REIT distribute annually at least 90% of its REIT taxable income (which does not equal net income as calculated in accordance with GAAP), determined without regard to the deduction for dividends paid and excluding net capital gains, and that it pay tax at regular corporate rates to the extent that it annually distributes less than 100% of its REIT taxable income. We generally intend over time to pay quarterly distributions in an amount at least equal to our REIT taxable income.

Ownership limit

To assist us in complying with the limitations on the concentration of ownership of a REIT imposed by the Internal Revenue Code of 1986, as amended, or the “Internal Revenue Code,” among other purposes, our charter prohibits, with certain exceptions, any individuals (including certain entities treated as individuals for this purpose) from beneficially or constructively owning, applying certain attribution

rules under the Internal Revenue Code, more than 9.9% by value or number of shares, whichever is more restrictive, of the outstanding shares of our class A common stock, or 9.9% by value or number of shares, whichever is more restrictive, of the outstanding shares of our capital stock.

NYSE symbol

“BXMT”

Risk factors

An investment in the shares of our class A common stock involves risks, and prospective investors should carefully consider the matters discussed under “Risk Factors” beginning on page S-5 of this prospectus supplement and the reports we file with the SEC pursuant to the Exchange Act, incorporated by reference into this prospectus supplement and the accompanying prospectus, before making a decision to invest in shares of our class A common stock.

(1)

The number of shares of our class A common stock to be outstanding after this offering is based on 81,731,236 shares of our class A common stock outstanding as of May 29, 2015. The number of outstanding shares as of May 29, 2015 excludes (i) 6,019,266 shares of our class A common stock issuable upon conversion of our 5.25% Convertible Senior Notes due 2018 based on the initial conversion rate; (ii) 126,454 shares of our class A common stock issuable upon conversion of deferred stock units held by members of our board of directors; and (iii) 751,985 shares of our class A common stock reserved for issuance pursuant to our stock incentive plans.

Before you invest in shares of our class A common stock, in addition to the other information in this prospectus supplement and the accompanying prospectus, you should carefully read and consider the risk factors described below as well as under the heading “Risk Factors” contained in Part I, Item 1A in our Annual Report on Form 10-K for the fiscal year ended December 31, 2014 and in Part II, Item 1A in our Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2015, as filed with the SEC on April 28, 2015, each of which is incorporated by reference into this prospectus supplement and the accompanying prospectus, as the same may be updated from time to time by our future filings under the Exchange Act. Each of the risks described in these documents could materially and adversely affect our business, financial condition, results of operations and prospects, and could result in a partial or complete loss of your investment.

In connection with the forward-looking statements that appear in this prospectus supplement and the accompanying prospectus, you should also carefully review the cautionary statement referred to under “Forward-Looking Statements” in this prospectus supplement.

The capital and credit markets have experienced periods of extreme volatility and disruption in recent years. The market price and liquidity of the market for shares of our class A common stock may be significantly affected by numerous factors, some of which are beyond our control and may not be directly related to our operating performance. Some of the factors that could negatively affect the market price of our class A common stock include:

As noted above, market factors unrelated to our performance could also negatively impact the market price of our class A common stock. One of the factors that investors may consider in deciding whether to buy or sell our class A common stock is our distribution rate as a percentage of our stock price relative to market interest rates. If market interest rates increase, prospective investors may demand a higher distribution rate or seek alternative investments paying higher dividends or interest. As a result, interest rate fluctuations and conditions in the capital markets may affect the market value of our class A common stock.

Some provisions of our charter and bylaws and Maryland law may deter takeover attempts, which may limit the opportunity of our stockholders to sell their shares at a favorable price.

Some of the provisions of Maryland law and our charter and bylaws discussed below could make it more difficult for a third party to acquire us, even if doing so might be beneficial to our stockholders by providing them with the opportunity to sell their shares at a premium to the then current market price.

Issuance of Stock Without Stockholder Approval. Our charter authorizes our board of directors, without stockholder approval, to authorize the issuance of up to 100,000,000 shares of preferred stock and up to 200,000,000 shares of class A common stock. Our charter also authorizes our board of directors, without stockholder approval, to classify or reclassify any unissued shares of our class A common stock and preferred stock into other classes or series of stock and a majority of our entire board of directors, without stockholder approval, may amend our charter to increase or decrease the aggregate number of shares of stock or the number of shares of stock of any class or series that are authorized by the charter to be issued. Preferred stock may be issued in one or more classes or series, the terms of which shall be determined by our board of directors without further action by stockholders. Prior to issuance of any such class or series, our board of directors will set the terms of any such class or series, including the preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications and terms or conditions of redemption. The issuance of any preferred stock could materially adversely affect the rights of holders of our class A common stock and, therefore, could reduce the value of the class A common stock. In addition, specific rights granted to future holders of our preferred stock could be used to restrict our ability to merge with, or sell assets to, a third party. The power of our board of directors to cause us to issue preferred stock could, in certain circumstances, make it more difficult, delay, discourage, prevent or make it more costly to acquire or effect a change in control, thereby preserving the current stockholders’ control.

Advance Notice Bylaw. Our bylaws contain advance notice procedures for the introduction by a stockholder of new business and the nomination of directors by a stockholder. These provisions could, in certain circumstances, discourage proxy contests and make it more difficult for you and other stockholders to elect stockholder-nominated directors and to propose and, consequently, approve stockholder proposals opposed by management.

Maryland Takeover Statutes. We are subject to the Maryland Business Combination Act, which could delay or prevent an unsolicited takeover of us. The statute substantially restricts the power of third parties who acquire, or seek to acquire, control of us to complete mergers and other business combinations without the approval of our board of directors even if such transaction would be beneficial to stockholders. “Business combinations” between such a third party acquirer or its affiliate and us are prohibited for five years after the most recent date on which the acquirer becomes an “interested stockholder.” An “interested stockholder” is defined as (a) any person who beneficially owns 10% or more of the voting power of our outstanding voting stock or (b) an affiliate or associate of ours who, at any time within the two-year period immediately prior to the date in question, was the beneficial owner of 10% or more of the voting power of our then outstanding stock. If our board of directors approved in advance the transaction that would otherwise give rise to the acquirer attaining such status, the acquirer would not become an interested stockholder and, as a result, it could enter into a business combination with us. Our board of directors may, however, provide that its approval is subject to compliance, at or after the time of approval, with any terms and conditions determined by the board of directors. After the lapse of the five-year prohibition period, any business combination between us and an interested stockholder generally must be recommended by our board of directors and approved by the affirmative vote of at least:

The super-majority vote requirements do not apply if the transaction complies with a minimum price and form of consideration requirements prescribed by the statute.

The statute permits various exemptions from its provisions, including business combinations that are exempted by the board of directors prior to the time that an interested stockholder becomes an interested stockholder. Our board of directors has exempted any business combination involving a limited liability company indirectly controlled by a trust for the benefit of Samuel Zell, our former chairman of the board, and his family and approved in advance the issuance of shares to W.R. Berkley. In addition, our board of directors has exempted any business combination involving Huskies Acquisition LLC, or “Huskies Acquisition,” an affiliate of Blackstone, or its present affiliates or Blackstone and its present and future affiliates; provided, however, that Huskies Acquisition or any of its present affiliates and Blackstone and any of its present or future affiliates may not enter into any “business combination” with us without the prior approval of at least a majority of the members of our board of directors who are not affiliates or associates of Huskies Acquisition or Blackstone. As a result, these parties may enter into business combinations with us without compliance with the five-year prohibition or the super-majority vote requirements and the other provisions of the statute.

We are also subject to the Maryland Control Share Acquisition Act. With certain exceptions, the Maryland General Corporation Law provides that a holder of “control shares” of a Maryland corporation acquired in a “control share acquisition” has no voting rights except to the extent approved by a vote of two-thirds of the votes entitled to be cast on the matter, excluding shares owned by the acquiring person or by our officers or by our directors who are also our employees.

Control shares are voting shares of stock which, if aggregated with all other shares of stock owned by the acquirer or in respect of which the acquirer is able to exercise or direct the exercise of voting power (except solely by virtue of a revocable proxy), would entitle the acquirer to exercise voting power in electing directors within one of the specified ranges of voting power. Control shares do not include shares the acquirer is then

entitled to vote as a result of having previously obtained stockholder approval. A control share acquisition means the acquisition of issued and outstanding control shares, subject to certain exceptions. A person who has made or proposes to make a control share acquisition, upon satisfaction of certain conditions, including an undertaking to pay expenses, may compel our board to call a special meeting of stockholders to be held within 50 days of demand to consider the voting rights of the control shares in question. If no request for a meeting is made, we may present the question at any stockholders meeting.

If voting rights are not approved at a stockholders meeting or if the acquiring person does not deliver the statement required by Maryland law, then, subject to certain conditions and limitations, we may redeem for fair value (determined without regard to the absence of voting rights) any or all of the control shares, except those for which voting rights have previously been approved. If voting rights for control shares are approved at a stockholders meeting and the acquirer may then vote a majority of the shares entitled to vote, then all other stockholders may exercise appraisal rights. The fair value of the shares for purposes of these appraisal rights may not be less than the highest price per share paid by the acquirer in the control share acquisition. The control share acquisition statute does not apply to shares acquired in a merger, consolidation or share exchange if we are a party to the transaction, nor does it apply to acquisitions approved or exempted by our charter or bylaws. Our bylaws contain a provision exempting the following persons from this statute: (i) a limited liability company indirectly controlled by a trust for the benefit of Samuel Zell and his family; (ii) W.R. Berkley Corporation and any of its controlled affiliates; and (iii) Huskies Acquisition, or any person or entity that was an affiliate of Huskies Acquisition as of September 27, 2012 or by Blackstone or any of its affiliates.

We are also eligible to elect to be subject to the Maryland Unsolicited Takeovers Act, which permits our board of directors, without stockholder approval, to, among other things and notwithstanding any provision in our charter or bylaws, elect on our behalf to classify the terms of directors and to increase the stockholder vote required to remove a director. Such an election would significantly restrict the ability of third parties to wage a proxy fight for control of our board of directors as a means of advancing a takeover offer. If an acquirer were discouraged from offering to acquire us, or prevented from successfully completing a hostile acquisition, you could lose the opportunity to sell your shares at a favorable price.

Our charter contains provisions that are designed to reduce or eliminate duties of Blackstone and our directors with respect to corporate opportunities and competitive activities.

Our charter contains provisions designed to reduce or eliminate duties of Blackstone and its affiliates (as such term is defined in the charter), and of our directors or any person our directors control to refrain from competing with us or to present to us business opportunities that otherwise may exist in the absence of such charter provisions. Under our charter, Blackstone and its affiliates and our directors or any person that our directors control will not be obligated to present to us opportunities unless those opportunities are expressly offered to such person in his or her capacity as a director or officer of Blackstone Mortgage Trust and those persons will be able to engage in competing activities without any restriction imposed as a result of Blackstone’s or its affiliates’ status as a stockholder or Blackstone’s affiliates’ status as officers or directors of Blackstone Mortgage Trust.

We have not established a minimum distribution payment level and we cannot assure you of our ability to pay distributions in the future.

We are generally required to distribute to our stockholders at least 90% of our REIT taxable income each year for us to qualify as a REIT under the Internal Revenue Code, which requirement we currently intend to satisfy through quarterly distributions of all or substantially all of our REIT taxable income in such year, subject to certain adjustments. Although we intend to make regular quarterly distributions to holders of our class A common stock and we generally intend to pay quarterly distributions in an amount at least equal to our REIT taxable income, we have not established a minimum distribution payment level and our ability to pay distributions may be adversely affected by a number of factors, including the risk factors described in this

prospectus supplement and the documents incorporated by reference herein. All distributions will be made at the discretion of our board of directors and will depend on our earnings, our financial condition, debt covenants, maintenance of our REIT qualification, applicable law and other factors as our board of directors may deem relevant from time to time. We believe that a change in any one of the following factors could adversely affect our results of operations and impair our ability to pay distributions to our stockholders:

As a result, no assurance can be given that the level of any distributions we make to our stockholders will achieve a market yield or increase or even be maintained over time, any of which could materially and adversely affect the market price of our class A common stock. We may use our net operating losses, to the extent available, carried forward to offset future REIT taxable income, and therefore reduce our dividend requirements. In addition, some of our distributions may include a return of capital, which would reduce the amount of capital available to operate our business.

In addition, distributions that we make to our stockholders will generally be taxable to our stockholders as ordinary income. However, a portion of our distributions may be designated by us as long-term capital gains to the extent that they are attributable to capital gain income recognized by us or may constitute a return of capital to the extent that they exceed our earnings and profits as determined for U.S. federal income tax purposes. A return of capital is not taxable, but has the effect of reducing the basis of a stockholder’s investment in our class A common stock.

The investments that we make in accordance with our investment objectives may result in a high amount of risk when compared to alternative investment options and volatility or loss of principal. Our investments may be highly speculative and aggressive, and therefore an investment in our class A common stock may not be suitable for someone with lower risk tolerance.

Future issuances of equity or debt securities, which may include securities that would rank senior to our class A common stock, may dilute the ownership interest of our existing holders of class A common stock and adversely affect the market price of the shares of our class A common stock.

The issuance of additional shares of our class A common stock in this offering, or in connection with the conversion of our outstanding 5.25% Convertible Senior Notes due 2018, or other future issuances of our class A common stock or shares of preferred stock or securities convertible or exchangeable into equity securities, may dilute the ownership interest of our existing holders of class A common stock.

If we decide to issue debt or equity securities which would rank senior to our class A common stock, it is likely that they will be governed by an indenture or other instrument containing covenants restricting our operating flexibility. Additionally, any convertible or exchangeable securities that we issue may have rights, preferences and privileges more favorable than those of our class A common stock and may result in dilution to owners of our class A common stock. We and, indirectly, our stockholders will bear the cost of issuing and servicing such securities. Because our decision to issue additional equity or debt securities in any future offering will depend on market conditions and other factors beyond our control, we cannot predict or estimate the amount,

timing or nature of our future issuances. Also, we cannot predict the effect, if any, of future sales of our class A common stock, or the availability of shares for future sales, on the market price of our class A common stock. Sales of substantial amounts of class A common stock or the perception that such sales could occur may adversely affect the prevailing market price for the shares of our class A common stock. Thus holders of our class A common stock will bear the risk of our future issuances reducing the market price of our class A common stock and diluting the value of their stock holdings in us.

We estimate that the net proceeds we will receive from this offering will be approximately $ million after deducting estimated offering expenses payable by us of approximately $350,000 (or, if the underwriters exercise their option to purchase 1,500,000 additional shares of class A common stock in full, approximately $ million after deducting estimated offering expenses payable by us of approximately $350,000).

We plan to use substantially all of the net proceeds from this offering to originate and purchase additional commercial mortgage loans and other target assets and investments consistent with our investment strategies and investment guidelines. We may also use a portion of the net proceeds for working capital and other general corporate purposes, as described in more detail below.

We focus on originating and purchasing senior loans collateralized by commercial properties in North America and Europe. We also have originated or acquired and may continue to originate or acquire other real estate and real estate-related debt assets. The allocation of our capital among our target assets will depend on prevailing market conditions and may change over time in response to different prevailing market conditions, including with respect to interest rates and general economic and credit market conditions. In addition, we also may use the net proceeds from this offering to invest in assets other than our target assets, subject to maintaining our qualification as a REIT for U.S. federal income tax purposes and our exclusion from regulation under the Investment Company Act. Until appropriate investments can be identified, our Manager may invest the net proceeds from this offering in money market funds, bank accounts, overnight repurchase agreements with primary federal reserve bank dealers collateralized by direct U.S. government obligations and other instruments or investments reasonably determined by our Manager to be of high quality and that are consistent with our intention to qualify as a REIT and maintain our exclusion from regulation under the Investment Company Act. These investments are expected to provide a lower net return than we seek to achieve from our target assets.

The following table sets forth our consolidated cash and cash equivalents and capitalization as of March 31, 2015 on:

The following table does not reflect the incurrence or repayment of debt since March 31, 2015, other than borrowings under the Wells Fargo facility. The following table should be read in conjunction with the pro forma financial information included in exhibit 99.1 to our Current Report on Form 8-K filed with the SEC on April 17, 2015 which is incorporated herein by reference.

The following is a summary of the terms of our class A common stock and preferred stock, certain provisions of the Maryland General Corporation Law and provisions of our charter and bylaws containing the material terms of our class A common stock and preferred stock, which are qualified in their entirety by reference to the Maryland General Corporation Law, our charter and bylaws. Copies of our charter and bylaws are filed as exhibits to the registration statement of which this prospectus supplement is part. See “Where You Can Find More Information.”

Under our charter, we may issue up to 300,000,000 shares of stock comprised of the following:

As of May 29, 2015, 81,731,236 shares of our class A common stock were issued and outstanding and no shares of preferred stock were designated as a particular class or series or are outstanding. Under Maryland law, our stockholders generally are not liable for our debts or obligations. The class A common stock is listed on the NYSE under the symbol “BXMT”.

No warrants to purchase either class A common stock or preferred stock were issued or outstanding as of the date of this prospectus supplement.

Our charter authorizes our board of directors, without stockholder approval, to:

We believe that the power to (i) issue additional shares of our class A common stock or preferred stock, (ii) increase the aggregate number of shares of stock of any class or series that we have the authority to issue and (iii) classify or reclassify unissued shares of our class A common or preferred stock and thereafter to issue the classified or reclassified shares of stock, provides us with increased flexibility in structuring possible future financings and acquisitions and in meeting other needs which might arise. In addition, under Maryland law, our board of directors may authorize the amendment of our charter to effect a reverse stock split that results in a combination of shares of stock at a ratio of not more than ten shares of stock into one share of stock in any 12-month period. These actions may be taken without stockholder approval, unless stockholder approval is required by applicable law or the rules of any stock exchange or automated quotation system on which our securities may be listed or traded.

Prior to the issuance of shares of each class or series, our board of directors is required by Maryland law and by our charter to set, subject to our charter restrictions on ownership and transfers of our stock, the terms, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications and terms or conditions of redemption for each class or series. Thus, our board of directors could authorize the issuance of shares of common stock or preferred stock with terms and conditions which could have the effect of delaying, deferring or preventing a transaction or a change in control of Blackstone Mortgage Trust that might involve a premium price for holders of our class A common stock or otherwise be in their best interests.

Holders of our class A common stock are entitled to receive dividends when, as and if authorized by our board of directors and declared by us out of assets legally available for the payment of dividends. They are also entitled to share ratably in our assets legally available for distribution to our stockholders in the event of our liquidation, dissolution or winding up, after payment of, or adequate provision for, all of our known debts and liabilities. These rights are subject to the preferential rights of any other class or series of our stock. All shares of class A common stock have equal dividend and liquidation rights.

Subject to law, the rights of any other class or series of our stock and our charter restrictions on ownership and transfer of our stock, each outstanding share of class A common stock is entitled to one vote on all matters submitted to a vote of the stockholders. There is no cumulative voting in the election of our directors and our directors are elected by a plurality of the votes cast, so the holders of a simple majority of the outstanding class A common stock, voting at a stockholders meeting at which a quorum is present, will have the power to elect all of the directors nominated for election at the meeting. Holders of our class A common stock generally have no exchange, sinking fund, redemption or appraisal rights, except the right to receive fair value in connection with certain control share acquisitions, and have no preemptive rights to subscribe for any of our securities. Because holders of our class A common stock do not have preemptive rights, we may issue additional shares of stock that may reduce each stockholder’s proportionate voting and financial interest in Blackstone Mortgage Trust. Rights to receive dividends on our class A common stock may be restricted by the terms of any future classified and issued shares of our stock.

Under Maryland law, a Maryland corporation generally cannot dissolve, amend its charter, convert to another form of entity, merge, sell all or substantially all of its assets, engage in a statutory share exchange or engage in similar transactions outside the ordinary course of business unless approved by the affirmative vote of stockholders holding at least two-thirds of the shares entitled to vote on the matter. However, a Maryland corporation may provide in its charter for approval of these matters by a lesser percentage, but not less than a majority of all of the votes entitled to be cast on the matter. Our charter provides for approval of these matters by a majority of all of the votes entitled to be cast on the matter.

We are authorized to issue 100,000,000 shares of preferred stock. As of the date of this prospectus supplement, no shares of preferred stock are outstanding. Our board of directors has the authority, without further action by the stockholders, to authorize us to issue shares of preferred stock in one or more class or series and to fix the number of shares, dividend rights, conversion rights, voting rights, redemption rights, liquidation preferences, sinking funds, and any other rights, preferences, privileges and restrictions applicable to each such series of preferred stock. The issuance of preferred stock could have the effect of making an attempt to gain control of us more difficult by means of a merger, tender offer, proxy contest or otherwise. The preferred stock, if issued, could have a preference on dividend payments that could affect our ability to make dividend distributions to the common stockholders.

Our transfer agent and registrar is American Stock Transfer & Trust Company, LLC located in Brooklyn, New York.

Our charter contains restrictions on the number of shares of our stock that a person may own. No individual (including certain entities treated as individuals for this purpose) may acquire or hold, directly or indirectly through application of constructive ownership rules, in excess of 9.9% in value or number, whichever is more restrictive, of our outstanding stock or our outstanding class A common stock unless they receive an exemption from our board of directors.

Subject to certain limitations, our board of directors, in its sole discretion, may exempt a person from, or modify, these limits, subject to such terms, conditions, representations and undertakings as it may determine. Our charter provides for, and our board of directors has granted, limited exemptions to certain persons who directly or indirectly own our stock, including directors, officers and stockholders controlled by them or trusts for the benefit of their families.

Our charter further prohibits any person from beneficially or constructively owning shares of our stock that would result in our being “closely held” under Section 856(h) of the Internal Revenue Code (without regard to whether the ownership interest is held during the last half of the taxable year) or otherwise cause us to fail to qualify as a REIT and any person from transferring shares of our stock if the transfer would result in our stock being owned by fewer than 100 persons. Any person who acquires or attempts or intends to acquire shares of our stock that may violate any of these restrictions, or who is the intended transferee of shares of our stock which are transferred to the trust, as described below, is required to give us immediate written notice, or in the case of a proposed or attempted transaction, give at least 15 days prior written notice, and provide us, at our principal executive office, with such information as we may request in order to determine the effect, if any, of the transfer on our status as a REIT. The above restrictions will not apply if our board of directors determines that it is no longer in our best interests to continue to qualify as a REIT or that compliance with such restrictions is no longer required for us to qualify as a REIT.

Any attempted transfer of our stock which, if effective, would result in violation of the above limitations, except for a transfer which results in shares being owned by fewer than 100 persons, in which case such transfer will be void and of no force and effect and the intended transferee shall acquire no rights in such shares, will cause the number of shares causing the violation, rounded to the nearest whole share, to be automatically transferred to a trust for the exclusive benefit of one or more charitable beneficiaries designated by us and the proposed transferee will not acquire any rights in the shares. The automatic transfer will be deemed to be effective as of the close of business on the business day, as defined in our charter, prior to the date of the transfer. Shares of our stock held in the trust will be issued and outstanding shares. The proposed transferee will not benefit economically from ownership of any shares of stock held in the trust, will have no rights to dividends and no rights to vote or other rights attributable to the shares of stock held in the trust. The trustee of the trust will have all voting rights and rights to dividends or other distributions with respect to shares held in the trust. These rights will be exercised for the exclusive benefit of the charitable beneficiaries. Any dividend or other distribution paid prior to our discovery that shares of stock have been transferred to the trust will be paid by the recipient to the trustee upon demand. Any dividend or other distribution authorized but unpaid will be paid when due to the trustee. Any dividend or distribution paid to the trustee will be held in trust for the charitable beneficiaries. Subject to Maryland law, effective as of the date that the shares have been transferred to the trustee, the trustee will have the authority to rescind as void any vote cast by the proposed transferee prior to our discovery that the shares have been transferred to the trust and to recast the vote in accordance with the desires of the trustee acting for the benefit of the charitable beneficiaries. However, if we have already taken irreversible corporate action, then the trustee will not have the authority to rescind and recast the vote.

interest of the charitable beneficiaries in the shares sold will terminate and the trustee will distribute the net proceeds of the sale to the proposed transferee and to the charitable beneficiaries as follows. The proposed transferee will receive the lesser of (i) the price paid by the proposed transferee for the shares or, if the proposed transferee did not give value for the shares in connection with the event causing the shares to be held in the trust, such as a gift, devise or other similar transaction, the market price, as defined in our charter, of the shares on the day of the event causing the shares to be held in the trust and (ii) the price per share received by the trustee from the sale or other disposition of the shares. Any net sale proceeds in excess of the amount payable per share to the proposed transferee will be paid immediately to the charitable beneficiaries. If, prior to our discovery that shares of our stock have been transferred to the trust, the shares are sold by the proposed transferee, then the shares shall be deemed to have been sold on behalf of the trust and, to the extent that the proposed transferee received an amount for the shares that exceeds the amount he was entitled to receive pursuant to the above, the excess shall be paid to the trustee upon demand.

In addition, shares of our stock held in the trust will be deemed to have been offered for sale to us, or our designee, at a price per share equal to the lesser of (i) the price per share in the transaction that resulted in the transfer to the trust, or, in the case of a devise or gift or similar transaction, the market price at the time of the devise or gift or similar transaction and (ii) the market price on the date we, or our designee, accept the offer. We will have the right to accept the offer until the trustee has sold the shares. Upon a sale to us, the interest of the charitable beneficiaries in the shares sold will terminate and the trustee will distribute the net proceeds of the sale to the proposed transferee.

If the transfer to the trust as described above is not automatically effective for any reason to prevent violation of the above limitations or our failing to qualify as a REIT, then the transfer of the number of shares that otherwise cause any person to violate the above limitations will be void and the intended transferee shall acquire no rights in such shares.

All certificates, if any, representing shares of our stock issued in the future will bear a legend referring to the restrictions described above.

Every owner of more than such percentage as may from time to time be established by our board of directors, or such lower percentage as required by the Internal Revenue Code or the treasury regulations promulgated thereunder, of our outstanding stock, within 30 days after the end of each taxable year, is required to give us written notice, stating his or her name and address, the number of shares of each class and series of our stock which he or she beneficially owns and a description of the manner in which the shares are held. Each such owner shall provide us with such additional information as we may request in order to determine the effect, if any, of its beneficial ownership on our status as a REIT and to ensure compliance with the aggregate stock ownership limit. In addition, each stockholder shall, upon demand, be required to provide us with such information as we may request in good faith in order to determine our status as a REIT and to comply with the requirements of any taxing authority or governmental authority or to determine such compliance.

These restrictions on ownership and transfer could delay, defer or prevent a transaction or a change in control that might involve a receipt of a premium price for the class A common stock or otherwise be in the best interest of the stockholders.

Under Maryland law, certain “business combinations” between a Maryland corporation and an interested stockholder or any affiliate of an interested stockholder are prohibited for five years after the most recent date on which the interested stockholder became an interested stockholder. These business combinations include a merger, consolidation, statutory share exchange, or, in circumstances specified in the statute, an asset transfer or issuance or reclassification of equity securities. An interested stockholder is defined as:

A person is not an interested stockholder under the statute if the board of directors approved in advance the transaction by which such person otherwise would have become an interested stockholder. However, in approving a transaction, the board of directors may provide that its approval is subject to compliance, at or after the time of approval, with any terms and conditions determined by the board.

After the five-year prohibition, any business combination between the Maryland corporation and an interested stockholder or any affiliate of an interested stockholder generally must be recommended by the board of directors of the corporation and approved by the affirmative vote of at least:

These super-majority vote requirements do not apply if the corporation’s common stockholders receive a minimum price, as defined under Maryland law, for their shares in the form of cash or other consideration in the same form as previously paid by the interested stockholder for its shares.

The statute permits various exemptions from its provisions, including business combinations that are exempted by the board of directors prior to the time that an interested stockholder becomes an interested stockholder. Our board of directors has exempted any business combination involving a limited liability company indirectly controlled by a trust for the benefit of Samuel Zell and his family. Our board of directors also approved in advance the transaction by which W.R. Berkley Corporation would have otherwise become an interested stockholder. In addition, our board of directors has exempted any business combination involving Huskies Acquisition LLC, or “Huskies Acquisition,” or its present affiliates or Blackstone and its present and future affiliates; provided, however, that Huskies Acquisition or any of its present affiliates and Blackstone and any of its present or future affiliates, may not enter into any “business combination” with Blackstone Mortgage Trust without the prior approval of at least a majority of the directors of our board of directors who are not affiliates or associates of Huskies Acquisition or Blackstone. As a result of the foregoing exemptions, these persons may enter into business combinations with us without compliance with the five-year prohibition, the super-majority vote requirements or the other provisions of the statute.

Maryland law provides that a holder of “control shares” of a Maryland corporation acquired in a “control share acquisition” has no voting rights with respect to such shares except to the extent approved by a vote of two-thirds of the votes entitled to be cast on the matter. A control share acquisition means the acquisition of control shares, subject to certain exceptions. Shares owned by the acquiror or by officers or directors of the target corporation who are also employees are excluded from shares entitled to vote on the matter. Control shares are voting shares of stock which, if aggregated with all other shares of stock owned by the acquiror or in respect of which the acquiror is able to exercise or direct the exercise of voting power, except solely by virtue of a revocable proxy, would entitle the acquiror to exercise voting power in electing directors within one of the following ranges of voting power:

Control shares do not include shares the acquiror is then entitled to vote as a result of having previously obtained stockholder approval or shares acquired directly from the corporation.

A person who has made or proposes to make a control share acquisition may compel the board of directors of the corporation to call a special meeting of stockholders to be held within 50 days of demand to consider the voting rights of the shares. The right to compel the calling of a special meeting is subject to the satisfaction of certain conditions, including an undertaking to pay the expenses of the meeting and delivering an “acquiring person statement” as described in the Maryland General Corporation Law. If no request for a meeting is made, the corporation may itself present the question at any stockholders meeting.

If voting rights are not approved at the meeting or if the acquiring person does not deliver an “acquiring person statement” as required by the statute, then the corporation may redeem for fair value any or all of the control shares, except those for which voting rights have previously been approved. The right of the corporation to redeem control shares is subject to certain conditions and limitations. Fair value is determined, without regard to the absence of voting rights for the control shares, as of the date of the last control share acquisition by the acquiror or, if a meeting of stockholders at which the voting rights of the shares are considered and not approved, as of the date of the meeting. If voting rights for control shares are approved at a stockholders meeting and the acquiror becomes entitled to vote a majority of the shares entitled to vote, all other stockholders may exercise appraisal rights, unless the charter or bylaws provide otherwise. The fair value of the shares as determined for purposes of appraisal rights may not be less than the highest price per share paid by the acquiror in the control share acquisition.

The control share acquisition statute does not apply to shares acquired in a merger, consolidation or statutory share exchange if the corporation is a party to the transaction, or to acquisitions approved or exempted by the charter or bylaws of the corporation. Our bylaws contain a provision exempting the following persons from this statute: (i) a limited liability company indirectly controlled by a trust for the benefit of Samuel Zell and his family; (ii) W.R. Berkley Corporation and any of its controlled affiliates; and (iii) Huskies Acquisition, or any person or entity that was an affiliate of Huskies Acquisition as of September 27, 2012 or by Blackstone or any of its affiliates.

The Maryland Unsolicited Takeovers Act applies to any Maryland corporation that has a class of equity securities registered under the Exchange Act and at least three independent directors. Pursuant to such act, the board of directors of any Maryland corporation satisfying such requirements, without obtaining stockholder approval and notwithstanding a contrary provision in its charter or bylaws, may elect to:

The Maryland Unsolicited Takeovers Act does not limit the power of a corporation to confer on the holders of any class or series of preferred stock the right to elect one or more directors. We currently have more than three independent directors and have a class of equity securities registered under the Exchange Act and therefore our board of directors could elect to provide for any of the foregoing provisions. As of the date hereof, our board of directors has not made any such election. However, through provisions of our bylaws unrelated to the Maryland Unsolicited Takeovers Act, we (a) vest in our board the exclusive power to fix the number of directors and (b) require for a stockholder requested meeting, the written request of stockholders entitled to cast not less than a majority of all the votes entitled to be cast.

Our bylaws provide that with respect to an annual meeting of stockholders, nominations of individuals for election to the board of directors and the proposal of business to be considered by stockholders may be made only:

With respect to special meetings of stockholders, only the business specified in our notice of the meeting may be brought before the meeting. Nominations of individuals for election to the board of directors at a special meeting may only be made:

Maryland law permits a Maryland corporation to include in its charter a provision limiting the liability of its directors and officers to the corporation and its stockholders for money damages except for liability resulting from (i) actual receipt of an improper benefit or profit in money, property or services or (ii) active and deliberate dishonesty which is established by a final judgment and which is material to the cause of action. Our charter contains such a provision which eliminates directors’ and officers’ liability to the maximum extent permitted by Maryland law.

Maryland law, to indemnify any present or former director or officer or any individual who, while a director or officer of our company and at our request, serves or has served another corporation, real estate investment trust, limited liability company, partnership, joint venture, trust, employee benefit plan or other enterprise as a director, officer, trustee, member, manager or partner and who is made or threatened to be made a party to, or witness in, the proceeding by reason of his or her service in that capacity from and against any claim or liability to which that individual may become subject or which that individual may incur by reason of his or her service in such capacity and to pay or reimburse his or her reasonable expenses in advance of final disposition of a proceeding. The rights to indemnification and advancement of expenses provided by our charter and our bylaws shall vest immediately upon an individual’s election as a director or officer. Our charter and bylaws also permit us to indemnify and advance expenses to any individual who served a predecessor of the company in any of the capacities described above and any employee or agent of the company or a predecessor of the company.

Maryland law requires a corporation (unless its charter provides otherwise, which our charter does not) to indemnify a director or officer who has been successful in the defense of any proceeding to which he is made or threatened to be made a party by reason of his service in that capacity. Maryland law permits a corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made or threatened to be made a party by reason of their service in those or other capacities unless it is established that (i) the act or omission of the director or officer was material to the matter giving rise to the proceeding and (a) was committed in bad faith or (b) was the result of active and deliberate dishonesty, (ii) the director or officer actually received an improper personal benefit in money, property or services or (iii) in the case of any criminal proceeding, the director or officer had reasonable cause to believe that the act or omission was unlawful. However, under Maryland law, a Maryland corporation may not indemnify for an adverse judgment in a suit by or in the right of the corporation or for a judgment of liability on the basis that personal benefit was improperly received, unless in either case a court orders indemnification and then only for expenses. In addition, Maryland law permits a corporation to advance reasonable expenses to a director or officer upon the corporation’s receipt of (i) a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation and (ii) a written undertaking by him or her or on his or her behalf to repay the amount paid or reimbursed by the corporation if it is ultimately determined that the standard of conduct was not met.

We have entered into indemnification agreements, or the “Indemnification Agreements,” with each of our directors and officers, each, an “Indemnitee.” The Indemnification Agreements provide that we will, subject to certain limitations and exceptions, indemnify, to the fullest extent permitted under Maryland law, and advance expenses to, each Indemnitee, in connection with (among other things) the Indemnitee’s capacity as a director, officer, employee or agent of Blackstone Mortgage Trust. This obligation includes, subject to certain terms and conditions, indemnification for any expenses (including reasonable attorneys’ fees), judgments, fines, penalties and settlement amounts actually and reasonably incurred by the Indemnitee in connection with any threatened or pending action, suit or proceeding. In certain instances, we may be required to advance such expenses, in which case the Indemnitee will be obligated to reimburse us for the amounts advanced if it is later determined that the Indemnitee is not entitled to indemnification for such expenses. The indemnification provided under the Indemnification Agreements is not exclusive of any other indemnity rights.

Our charter includes a provision that, among other things, subject to certain exceptions, none of Blackstone or its affiliates, our directors or any person that any of our directors control shall have any duty to refrain from engaging, directly or indirectly, in any business opportunities, including any business opportunities in the same or similar business activities or lines of business in which we or any of our affiliates may from time to time be engaged or propose to engage, or from competing with us.

Citigroup Global Markets Inc., Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan Securities LLC, Wells Fargo Securities, LLC and Morgan Stanley & Co. LLC are acting as joint book-running managers of this offering and as representatives of the underwriters named below. Subject to the terms and conditions stated in the underwriting agreement dated as of the date of this prospectus supplement, each underwriter named below has severally agreed to purchase, and we have agreed to sell to that underwriter, the number of shares of our class A common stock set forth opposite the underwriter’s name.

The underwriting agreement provides that the obligations of the underwriters to purchase the shares of our class A common stock included in this offering are subject to approval of legal matters by counsel and to other conditions. The underwriters will be obligated to purchase all the shares (other than those covered by the underwriters’ option to purchase additional shares of class A common stock) if they purchase any of the shares.

If the underwriters sell more shares than the total number set forth in the table above, we have granted to the underwriters an option, exercisable for 30 days from the date of this prospectus supplement, to purchase up to 1,500,000 additional shares of our class A common stock at the same price per share as the other shares purchased by the underwriters in this offering. To the extent the option is exercised, each underwriter must purchase a number of additional shares approximately proportionate to that underwriter’s initial purchase commitment. Any shares issued or sold under the underwriters’ option to purchase 1,500,000 additional shares of class A common stock will be issued and sold on the same terms and conditions as the other shares that are the subject of this offering.

The underwriters have agreed to purchase the shares of our class A common stock offered by this prospectus supplement at a price of $ per share, which will result in approximately $ million of total net proceeds to us before expenses payable by us (or approximately $ million if the underwriters’ option to purchase 1,500,000 additional shares of class A common stock is exercised in full). The underwriters propose to offer the shares of class A common stock offered hereby from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices, subject to receipt and acceptance by them and subject to their right to reject any order in whole or in part. The underwriters may effect such transactions by selling the shares of class A common stock to or through dealers and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or purchasers of shares of class A common stock for whom they may act as agents or to whom they may sell as principal. The difference between the price at which the underwriters purchase shares and the price at which the underwriters resell such shares may be deemed underwriting compensation.

We estimate that our total expenses for this offering will be approximately $350,000.

We have agreed to reimburse the underwriters for certain expenses relating to the Financial Industry Regulatory Authority, Inc., or “FINRA,” in an amount up to $10,000.

We have agreed to indemnify the underwriters against liabilities under the Securities Act, or contribute to payments that the underwriters may be required to make in that respect.

In compliance with the guidelines of FINRA, the aggregate maximum discount, commission or agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer will not exceed 8% of the offering proceeds from any offering pursuant to this prospectus supplement.

We have agreed that, for a period of 45 days after the date of this prospectus supplement, we will not, without the prior written consent of the representatives, dispose of or hedge any shares of our class A common stock or any securities convertible into or exchangeable for our class A common stock, subject to certain exceptions, including the issuance and sale of shares of class A common stock pursuant to an at-the-market program.

Each of our executive officers and directors, Blackstone Treasury Holdings III L.L.C., or “Holdings III,” our Manager and each of our Manager’s officers have agreed that, for a period of 45 days from the date of this prospectus supplement, they will not dispose of or hedge any shares of our class A common stock or any securities convertible into or exchangeable for our class A common stock, subject to certain exceptions. However, in the event that either (1) during the last 17 days of this 45-day “lock-up” period, we issue an earnings release or material news or a material event relating to us occurs, or (2) prior to the expiration of the “lock-up” period, we announce that we will release earnings results during the 16-day period beginning on the last day of the “lock-up” period, the restrictions described above shall continue to apply until the expiration of the 18-day period beginning on the date of the issuance of the earnings release or the occurrence of the material news or material event, as applicable, unless the representatives waive, in writing, such an extension. However, such extension will not apply if, within three business days prior to the 15th calendar day before the last day of the applicable 45-day restricted period, we deliver a certificate signed by our Chief Executive Officer or Chief Financial Officer, certifying that (i) our shares of class A common stock are “actively traded securities” as defined in Regulation M, and (ii) we meet the requirements set forth in paragraph (a)(1) of Rule 139 under the Securities Act.

The representatives may, in their sole discretion, release any of the securities subject to these lock-up agreements at any time without notice. There are no present agreements among the representatives, Holdings III, any of our executive officers or directors, our Manager, our Manager’s officers or us to release any of them or us from these lock-up agreements. However, we cannot predict the circumstances or timing under which these restrictions may be waived.

In connection with the offering, the underwriters may purchase and sell shares of class A common stock in the open market. Purchases and sales in the open market may include short sales, purchases to cover short positions, which may include purchases pursuant to the underwriters’ option to purchase additional shares of class A common stock, and stabilizing purchases.

Purchases to cover short positions and stabilizing purchases, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of our class A common stock. They may also cause the price of our class A common stock to be higher than the price that would otherwise exist in the open market in the absence of these transactions. The underwriters may conduct these transactions on the NYSE, in the over-the-counter market or otherwise. If the underwriters commence any of these transactions, they may discontinue them at any time.

In connection with the offering, certain of the underwriters or securities dealers may distribute prospectuses by electronic means, such as e-mail.

Certain of the underwriters are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, principal investment, hedging, financing and brokerage activities. The underwriters and their respective affiliates have in the past performed commercial banking, investment banking and advisory services for us and/or our affiliates, from time to time, for which they have received customary fees and reimbursement of expenses and may, from time to time, engage in transactions with and perform services for us and/or our affiliates in the ordinary course of their business for which they may receive customary fees and reimbursement of expenses. In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (which may include bank loans and/or credit default swaps) for their own account and for the accounts of their customers and may at any time hold long and/or short positions in such securities and instruments. Such investment and securities activities may involve our securities and instruments.

Certain of our special-purpose wholly-owned subsidiaries have entered into repurchase agreements with affiliates of certain of the underwriters, including: (i) a master repurchase agreement with Bank of America, N.A., an affiliate of Merrill Lynch, Pierce, Fenner & Smith Incorporated, that provides for advances of up to $750.0 million in the aggregate; (ii) a master repurchase agreement with Citibank N.A., an affiliate of Citigroup Global Markets Inc., that provides for advances of up to $500.0 million in the aggregate; (iii) a master repurchase agreement with JPMorgan Chase Bank, National Association, an affiliate of J.P. Morgan Securities LLC, that provides for advances of up to $250.0 million in the aggregate and another master repurchase agreement that provides for advances of up to £153.0 million in the aggregate; (iv) a master repurchase agreement with Wells Fargo Bank, National Association, an affiliate of Wells Fargo Securities, LLC that provides for advances of up to $1.0 billion in the aggregate and asset specific repurchase agreements that provide for approximately $159.8 million in advances in the aggregate; (v) a master repurchase agreement with Morgan Stanley Bank, N.A., an affiliate of Morgan Stanley & Co. LLC, that provides for advances of up to £250.0 million in the aggregate; and (vi) a master repurchase agreement with UBS Real Estate Securities Inc., an affiliate of UBS Securities LLC, that provides for advances of up to $103.1 million in the aggregate. In addition, we have from time to time purchased loans and other investments from affiliates of certain underwriters and we may purchase loans or other investments from affiliates of the underwriters in the future. We and our Manager are also party to equity distribution agreements with each of Citigroup Global Markets Inc., Wells Fargo Securities, LLC, JMP Securities LLC and Keefe, Bruyette & Woods, Inc. as sales agents to issue and sell shares of our class A common stock from time to time having an aggregate offering price of up to $200.0 million. Each sales agent is entitled to compensation with respect to any shares of class A common stock sold through it pursuant to the terms of the applicable equity distribution agreement.

In connection with the Loan Portfolio acquisition, an affiliate of Wells Fargo Securities, an underwriter for this offering, is providing us with $4.0 billion of secured financing, which we intend to use to finance a portion of the purchase price for the Loan Portfolio acquisition. Furthermore, certain affiliates of Wells Fargo Securities have been designated as purchasers with respect to certain loans and other assets to be sold by the sellers as part of the proposed acquisition of which the Loan Portfolio acquisition forms part. An affiliate of Wells Fargo Securities acted as the advisor to Blackstone and Wells Fargo in connection with the larger $23 billion acquisition by affiliates of Blackstone and Wells Fargo of the majority of GE Capital’s global real estate debt and equity business.

The shares purchased by certain affiliates of Blackstone in connection with this offering are an item of value that is deemed by FINRA to be included in the total underwriting compensation received by the underwriters in connection with this offering pursuant to FINRA Rule 5110.

No action has been taken in any jurisdiction (except in the United States) that would permit a public offering of our class A common stock, or the possession, circulation or distribution of this prospectus supplement or any other material relating to us or our class A common stock in any jurisdiction where action for that purpose is required. Accordingly, the shares of class A common stock may not be offered or sold, directly or indirectly, and neither this prospectus supplement nor any other offering material or advertisements in connection with our class A common stock may be distributed or published, in or from any country or jurisdiction, except in compliance with any applicable rules and regulations of any such country or jurisdiction.

Each of the underwriters may arrange to sell the class A common stock offered hereby in certain jurisdictions outside the United States, either directly or through affiliates, where they are permitted to do so.

This document is only being distributed to, and is only directed at (i) persons who have professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 as amended (the “Order”), (ii) persons falling within Article 49(2)(a) to (d) (high net worth companies, unincorporated associations, etc.) of the Order; or (iii) persons to whom an invitation or inducement to engage in investment activity (within the meaning of section 21 of the Financial Services and Markets Act 2000) in connection with the issue or sale of any securities may otherwise lawfully be communicated or caused to be communicated (all such persons together being referred to as “relevant persons”). Any investment or investment activity to which this document relates is available only to relevant persons and will be engaged in only with relevant persons. Any person who is not a relevant person should not act or rely on this document or any of its contents.

The shares may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong) and no advertisement, invitation or document relating to the shares may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to shares which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

The shares offered in this prospectus supplement have not been registered under the Financial Instruments and Exchange Act of Japan (the “Financial Instruments and Exchange Act”). The shares have not been offered or sold and will not be offered or sold, directly or indirectly, in Japan or to or for the account of any resident of Japan, except (i) pursuant to an exemption from the registration requirements of the Financial Instruments and Exchange Act and (ii) in compliance with any other applicable requirements of Japanese law.

This prospectus supplement has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and any other document or material in connection with the

offer or sale, or invitation for subscription or purchase, of the shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to compliance with conditions set forth in the SFA.

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

In addition, investors in Singapore should note that the securities acquired by them are subject to resale and transfer restrictions specified under Section 276 of the SFA, and they, therefore, should seek their own legal advice before effecting any resale or transfer of their securities.

This prospectus supplement relates to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority (“DFSA”). This prospectus supplement is intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. It must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement nor taken steps to verify the information set forth herein and has no responsibility for the prospectus supplement. The shares to which this prospectus supplement relates may be illiquid and/or subject to restrictions on their resale. Prospective purchasers of the shares offered should conduct their own due diligence on the shares. If you do not understand the contents of this prospectus supplement you should consult an authorized financial advisor.

The following summary describes the material United States federal income tax considerations relating to the ownership of class A common stock as of the date hereof by United States and non-United States holders, each as defined below. Except where noted, this summary deals only with class A common stock held as a capital asset and does not deal with special situations, such as those of dealers in securities or currencies, financial institutions, regulated investment companies, tax-exempt entities (except as described in “—Taxation of Tax-Exempt Holders of Our Class A Common Stock” below), insurance companies, persons holding class A common stock as a part of a hedging, integrated, conversion or constructive sale transaction or a straddle, traders in securities that elect to use a mark-to-market method of accounting for their securities holdings, persons liable for alternative minimum tax, investors in pass-through entities or United States holders of class A common stock whose “functional currency” is not the United States dollar. Furthermore, the discussion below is based upon the provisions of the Internal Revenue Code and United States Treasury Regulations, or “Treasury regulations,” rulings and judicial decisions thereunder as of the date hereof, and such authorities may be repealed, revoked or modified, possibly with retroactive effect, so as to result in United States federal income tax consequences different from those discussed below. No assurance can be given that the Internal Revenue Service, or “IRS,” would not assert, or that a court would not sustain, a position contrary to any of the tax consequences described below.

You should consult your own tax advisors concerning the United States federal income tax consequences in light of your particular situation as well as consequences arising under the laws of any other taxing jurisdiction.

Our election to be taxed as a REIT was effective January 1, 2003. We believe that we were organized and have operated and will continue to operate in such a manner as to qualify for taxation as a REIT under the United States federal income tax laws.

In connection with the filing of the accompanying prospectus, Simpson Thacher & Bartlett LLP rendered an opinion that, commencing with the taxable year ended December 31, 2008, Blackstone Mortgage Trust had been organized in conformity with the requirements for qualification and taxation as a REIT under the Internal Revenue Code, and its actual and proposed method of operation as described in the accompanying prospectus had enabled it, and would continue to enable it, to meet the requirements for qualification and taxation as a REIT under the Internal Revenue Code. Investors should be aware that the opinion of Simpson Thacher & Bartlett LLP is based upon customary assumptions, is conditioned upon certain representations made by us as to factual matters, including representations regarding the nature of our assets and the conduct of our business, and is not binding upon the IRS or any court. We have not received, and do not intend to seek, any rulings from the IRS regarding our status as a REIT or our satisfaction of the REIT requirements. The IRS may challenge our status a REIT, and a court could sustain any such challenge. In addition, the opinion of Simpson Thacher & Bartlett LLP is based on federal income tax law governing qualification as a REIT in effect as of the date thereof, which is subject to change either prospectively or retroactively. Moreover, our qualification and taxation as a REIT depend upon our ability to meet on a continuing basis, through actual annual operating results, certain qualification tests set forth in the federal tax laws. Those qualification tests involve the percentage of income that we earn from specified sources, the percentage of our assets that falls within specified categories, the diversity of the ownership of our shares, and the percentage of our earnings that we distribute. Simpson Thacher & Bartlett LLP will not review our compliance with those tests on a continuing basis. Accordingly, no assurance can be given that our actual results of operations for any particular taxable year will satisfy such requirements. For a discussion of the tax consequences of our failure to qualify as a REIT, see “—Failure to Qualify.”

discussion is qualified in its entirety by the applicable Internal Revenue Code provisions, rules and regulations promulgated thereunder, and administrative interpretations thereof.

In any year in which we qualify for taxation as a REIT, we generally will not be subject to United States federal income tax on that portion of our REIT taxable income that we distribute currently to our stockholders, although taxable income generated by domestic taxable REIT subsidiaries, if any, will be subject to regular corporate income tax. Our stockholders will generally be taxed on dividends that they receive at ordinary income rates unless such dividends are designated by us as capital gain dividends or qualified dividend income. Distributions we make are not eligible for the dividends received deduction for corporations. We expect that ordinary dividends paid by us generally will not be eligible for the reduced rate imposed on qualified dividend income received by individuals, trusts and estates.

We are generally not subject to United States corporate income tax on income that we distribute currently to stockholders, but we will be subject to United States federal tax as follows:

we will pay a 4% nondeductible excise tax on the excess of the required distribution over the amount we actually distributed, plus any retained amounts on which income tax has been paid at the corporate level.

In addition, notwithstanding our status as a REIT, we may also have to pay certain state and local income taxes, because not all states and localities treat REITs in the same manner that they are treated for United States federal income tax purposes. Moreover, as further described below, any domestic taxable REIT subsidiary in which we own an interest will be subject to United States federal corporate income tax on its net income.

Requirements for Qualification as a REIT. The Internal Revenue Code defines a REIT as a corporation, trust or association:

Conditions (1) through (4), inclusive, must be met during the entire taxable year. Condition (5) must be met during at least 335 days of a taxable year of 12 months, or during a proportionate part of a taxable year of less than 12 months other than the first taxable year for which an election to become a REIT is made. Condition (6) must be met during the last half of each taxable year but neither conditions (5) nor (6) apply to the first taxable year for which an election to become a REIT is made. We believe that we have maintained and will maintain sufficient diversity of ownership to allow us to continue to satisfy conditions (5) and (6) above. In addition, our charter contains restrictions regarding the ownership and transfer of our stock that are intended to assist us in continuing to satisfy the share ownership requirements described in (5) and (6) above. The provisions of our charter restricting the ownership and transfer of our stock are described in the prospectus supplement under “Description of Capital Stock—Certain Provisions of Our Charter and Bylaws and of Maryland Law—REIT Qualification Restrictions on Ownership and Transfer.” These restrictions, however, may not ensure that we will be able to satisfy these share ownership requirements. If we fail to satisfy these share ownership requirements, we will fail to qualify as a REIT.

If we comply with regulatory rules pursuant to which we are required to send annual letters to holders of our stock requesting information regarding the actual ownership of our stock (as discussed below), and we do not know, or exercising reasonable diligence would not have known, whether we failed to meet requirement (6) above, we will be treated as having met the requirement.

To monitor compliance with the share ownership requirements, we generally are required to maintain records regarding the actual ownership of our shares. To do so, we must demand written statements each year from the record holders of significant percentages of our stock pursuant to which the record holders must disclose the actual owners of the shares (i.e., the persons required to include our dividends in their gross income). We must maintain a list of those persons failing or refusing to comply with this demand as part of our records. We could be subject to monetary penalties if we fail to comply with these record-keeping requirements. If you fail or refuse to comply with the demands, you will be required by Treasury regulations to submit a statement with your tax return disclosing your actual ownership of our shares and other information. In addition, we must satisfy all relevant filing and other administrative requirements established by the IRS to elect and maintain REIT status, use a calendar year for federal income tax purposes, and comply with the record keeping requirements of the Internal Revenue Code and regulations promulgated thereunder.

Ownership of Partnership Interests. In the case of a REIT that is a partner in an entity that is treated as a partnership for United States federal income tax purposes, Treasury regulations provide that the REIT is deemed to own its proportionate share of the partnership’s assets and to earn its proportionate share of the partnership’s gross income based on its pro rata share of capital interests in the partnership for purposes of the asset and gross income tests applicable to REITs, as described below. However, solely for purposes of the 10% value test, described below (see “—Asset Tests”), the determination of a REIT’s interest in partnership assets will be based on the REIT’s proportionate interest in any securities issued by the partnership, excluding for these purposes, certain excluded securities as described in the Internal Revenue Code. In addition, the assets and gross income of the partnership generally are deemed to retain the same character in the hands of the REIT. Thus, our proportionate share of the assets and items of income of partnerships in which we own an equity interest is treated as assets and items of income of our company for purposes of applying the REIT requirements described below. Consequently, to the extent that we directly or indirectly hold a preferred or other equity interest in a partnership, the partnership’s assets and operations may affect our ability to qualify as a REIT, even though we may have no control or only limited influence over the partnership.

Qualified REIT Subsidiaries. If a REIT owns a corporate subsidiary that is a “qualified REIT subsidiary,” the separate existence of that subsidiary is disregarded for United States federal income tax purposes. Generally, a qualified REIT subsidiary is a corporation, other than a taxable REIT subsidiary, all of the stock of which is owned directly or indirectly by the REIT. All assets, liabilities and items of income, deduction and credit of the qualified REIT subsidiary will be treated as assets, liabilities and items of income, deduction and credit of the REIT itself. A qualified REIT subsidiary of ours is not subject to United States federal corporate income taxation, although it may be subject to state and local taxation in some states.

In the event that a qualified REIT subsidiary ceases to be wholly-owned by us (for example, if any equity interest in the subsidiary is acquired by a person other than us or another disregarded subsidiary of us), the subsidiary’s separate existence would no longer be disregarded for United States federal income tax purposes. Instead, it would have multiple owners and would be treated as either a partnership or a taxable corporation. Such an event could, depending on the circumstances, adversely affect our ability to satisfy the various asset and gross income tests applicable to REITs, including the requirement that REITs generally may not own, directly or indirectly, more than 10% of the value or voting power of the outstanding securities of another corporation. See “—Asset Tests” and “—Income Tests.”

Taxable REIT Subsidiaries. A “taxable REIT subsidiary” is an entity that is taxable as a corporation in which we directly or indirectly own stock and that elects with us to be treated as a taxable REIT subsidiary. In addition, if a taxable REIT subsidiary owns, directly or indirectly, securities representing 35% or more of the vote or value of a subsidiary corporation, that subsidiary will also be treated as a taxable REIT subsidiary. However, an entity will not qualify as a taxable REIT subsidiary if it directly or indirectly operates or manages a lodging or health care facility or, generally, provides to another person, under a franchise, license or otherwise, rights to any brand name under which any lodging facility or health care facility is operated. We generally may not own more than 10%, as measured by voting power or value, of the securities of a corporation that is not a qualified REIT subsidiary unless we and such corporation elect to treat such corporation as a taxable REIT subsidiary. Overall, no more than 25% of the value of a REIT’s assets may consist of stock or securities of one or more taxable REIT subsidiaries.

Income earned by a taxable REIT subsidiary is not attributable to the REIT. As a result, income that might not be qualifying income for purposes of the income tests applicable to REITs could be earned by a taxable REIT subsidiary without affecting our status as a REIT.

payments that we receive from, or on certain expenses deducted by, a taxable REIT subsidiary if the IRS were to assert successfully that the economic arrangements between us and a taxable REIT subsidiary are not comparable to similar arrangements among unrelated parties.

Taxable Mortgage Pools and REMICs. An entity, or a portion of an entity, that does not elect to be treated as a REMIC may be classified as a taxable mortgage pool under the Internal Revenue Code if:

Under the Treasury regulations, if less than 80% of the assets of an entity (or a portion of an entity) consists of debt obligations, these debt obligations are considered not to comprise “substantially all” of its assets, and therefore the entity would not be treated as a taxable mortgage pool. It is possible that certain of our financing activities, including securitizations, will result in the treatment of us or a portion of our assets as a taxable mortgage pool.

An entity or portion of an entity will be treated as a REMIC for purposes of the Internal Revenue Code if:

Where an entity, or a portion of an entity, is classified as a taxable mortgage pool, it is generally treated as a taxable corporation for federal income tax purposes. In the case of a REIT, a portion of a REIT, or a REIT subsidiary that is disregarded as a separate entity from the REIT that is a taxable mortgage pool, however, special rules apply. The portion of a REIT’s assets, held directly or through a REIT subsidiary that is disregarded as a separate entity from the REIT, that qualifies as a taxable mortgage pool is treated as a qualified REIT subsidiary that is not subject to corporate income tax, and the taxable mortgage pool classification does not directly affect the tax status of the REIT. The Treasury Department has yet to issue regulations governing the tax treatment of the stockholders of a REIT that owns an interest in a taxable mortgage pool.

A portion of our income from a REMIC residual interest or taxable mortgage pool arrangement could be treated as “excess inclusion income.” Excess inclusion income is an amount, with respect to any calendar quarter, equal to the excess, if any, of (i) income allocable to the holder of a residual interest in a REMIC or taxable mortgage pool interest during such calendar quarter over (ii) the sum of an amount for each day in the calendar quarter equal to the product of (a) the adjusted issue price of the interest at the beginning of the quarter multiplied by (b) 120 percent of the long-term federal rate (determined on the basis of compounding at the close of each calendar quarter and properly adjusted for the length of such quarter).

Our excess inclusion income would be allocated among our stockholders in proportion to dividends paid. A stockholder’s share of excess inclusion income (i) would not be allowed to be offset by any net operating losses otherwise available to the stockholder, (ii) would be subject to tax as unrelated business taxable income in the hands of most types of stockholders that are otherwise generally exempt from United States federal income tax and (iii) would result in the application of United States federal income tax withholding at the maximum rate (30%), without reduction for any otherwise applicable income tax treaty, to the extent allocable to most types of non-United States stockholders. See “—Taxation of Non-United States Holders of Our Class A Common Stock—Distributions.” Although the law on this matter is not clear with regard to taxable mortgage pool interests, to the extent excess inclusion income is allocated to a tax-exempt stockholder of ours that is not subject to unrelated business income tax (such as a government entity), we would be taxable on this income at the highest applicable corporate tax rate (currently 35%). The manner in which excess inclusion income would be allocated among shares of different classes of our stock or how such income is to be reported to stockholders is not clear under current law. Tax-exempt investors, non-United States investors and taxpayers with net operating losses should carefully consider the tax consequences described above and are urged to consult their tax advisors in connection with their decision to invest in our class A common stock.

If a subsidiary partnership of ours, not wholly-owned by us directly or through one or more disregarded entities, were a taxable mortgage pool, the foregoing rules would not apply. Rather, the partnership that is a taxable mortgage pool would be treated as a corporation for United States federal income tax purposes, and would potentially be subject to corporate income tax. In addition, this characterization would alter our REIT income and asset test calculations and could adversely affect our compliance with those requirements.

To qualify as a REIT, we must satisfy two gross income requirements, each of which is applied on an annual basis. First, at least 75% of our gross income, excluding gross income from prohibited transactions and certain hedging and foreign currency transactions, for each taxable year generally must be derived directly or indirectly from:

Second, at least 95% of our gross income, excluding gross income from prohibited transactions and certain hedging transactions, for each taxable year must be derived from sources that qualify for purposes of the 75% test, and from (i) dividends, (ii) interest and (iii) gain from the sale or disposition of stock or securities.

If we fail to satisfy one or both of the 75% and 95% gross income tests for any taxable year, we may nevertheless qualify as a REIT for that year if we are entitled to relief under the Internal Revenue Code. These relief provisions generally will be available if our failure to meet the tests is due to reasonable cause and not due to willful neglect, and we attach a schedule of the sources of our income to our United States federal income tax return. It is not possible, however, to state whether in all circumstances we would be entitled to the benefit of these relief provisions. For example, if we fail to satisfy the gross income tests because nonqualifying income that we intentionally recognize exceeds the limits on nonqualifying income, the IRS could conclude that the failure to satisfy the tests was not due to reasonable cause. If these relief provisions are inapplicable to a particular set of circumstances, we will fail to qualify as a REIT. Even if these relief provisions apply, a penalty tax would be imposed based on the amount of nonqualifying income. See “—Our Taxation as a REIT.”

Gross income from our sale of property that we hold primarily for sale to customers in the ordinary course of business is excluded from both the numerator and the denominator in both gross income tests. In addition, income and gain from hedging transactions that we enter into to hedge indebtedness incurred or to be incurred to acquire or carry real estate assets and that are clearly and timely identified as such will be excluded from both the numerator and the denominator for purposes of both gross income tests. In addition, certain foreign currency gains will be excluded from gross income for purposes of one or both of the gross income tests. We will monitor the amount of our non-qualifying income and we will manage our portfolio to comply at all times with the gross income tests. The following paragraphs discuss some of the specific applications of the gross income tests to us.

Dividends. Our dividend income from stock in any corporation (other than any REIT) and from any taxable REIT subsidiary will be qualifying income for purposes of the 95% gross income test, but not the 75% gross income test. If we own stock in other REITs, the dividends that we receive from those REITs and our gain on the sale of the stock in those REITs will be qualifying income for purposes of both gross income tests. However, if a REIT in which we own stock fails to qualify as a REIT in any year, our income from such REIT would be qualifying income for purposes of the 95% gross income test, but not the 75% gross income test.

Interest. The term “interest,” as defined for purposes of both gross income tests, generally excludes any amount that is based in whole or in part on the income or profits of any person, however, it generally includes the following: (i) an amount that is received or accrued based on a fixed percentage or percentages of receipts or sales, and (ii) an amount that is based on the income or profits of a debtor, as long as the debtor derives substantially all of its income from the real property securing the debt by leasing substantially all of its interest in the property, and only to the extent that the amounts received by the debtor would be qualifying “rents from real property” if received directly by a REIT. We do not expect that any of our loans will be based in whole or in part on the income or profits of any person.

Interest on debt secured by mortgages on real property or on interests in real property, including, for this purpose, prepayment penalties, loan assumption fees and late payment charges that are not compensation for services, generally is qualifying income for purposes of the 75% gross income test. However, if the highest principal amount of a loan outstanding during a taxable year exceeds the fair market value of the real property securing the loan as of the date we agreed to originate or acquire the loan, a portion of the interest income from such loan will not be qualifying income for purposes of the 75% gross income test but will be qualifying income for purposes of the 95% gross income test. The portion of the interest income that will not be qualifying income for purposes of the 75% gross income test will be equal to the portion of the principal amount of the loan that is not secured by real property—that is, the amount by which the loan exceeds the value of the real estate that is security for the loan.

on such mortgage loans would be qualifying income for purposes of the 75% gross income test to the extent that the obligation is secured by real property, as discussed above. In the case of CMBS and RMBS treated as interests in a REMIC, income derived from REMIC interests will generally be treated as qualifying income for purposes of the 75% and 95% gross income tests. If less than 95% of the assets of the REMIC are real estate assets, however, then only a proportionate part of our interest in the REMIC and income derived from the interest will qualify for purposes of the 75% gross income test. In addition, some REMIC securitizations include imbedded interest swap or cap contracts or other derivative instruments that potentially could produce non-qualifying income for the holder of the related REMIC securities.

The interest, original issue discount, and market discount income that we will receive from our mortgage-related assets generally will be qualifying income for purposes of both gross income tests.

Hedging Transactions. We may enter into hedging transactions with respect to one or more of our assets or liabilities. Hedging transactions could take a variety of forms, including interest rate swap agreements, interest rate cap agreements, options, futures contracts, forward rate agreements or similar financial instruments. Except to the extent provided by Treasury regulations, any income from a hedging transaction we enter into (1) in the normal course of our business primarily to manage risk of interest rate or price changes or currency fluctuations with respect to borrowings made or to be made, or ordinary obligations incurred or to be incurred, to acquire or carry real estate assets, which is clearly identified as specified in Treasury regulations before the close of the day on which it was acquired, originated or entered into, including gain from the sale or disposition of such a transaction, or (2) primarily to manage risk of currency fluctuations with respect to any item of income or gain that would be qualifying income under the 75% or 95% income tests which is clearly identified as such before the close of the day on which it was acquired, originated or entered into, will not constitute gross income for purposes of the 75% or 95% gross income tests. To the extent that we enter into other types of hedging transactions, the income from those transactions is likely to be treated as non-qualifying income for purposes of both of the 75% and 95% gross income tests. We intend to structure any hedging transactions in a manner that does not jeopardize our qualification as a REIT.

We may conduct some or all of our hedging activities through a taxable REIT subsidiary or other corporate entity, the income of which may be subject to United States federal income tax, rather than by participating in the arrangements directly or through pass-through subsidiaries.

Fee Income. Fee income generally will be qualifying income for purposes of both the 75% and 95% gross income tests if it is received in consideration for entering into an agreement to make a loan secured by real property and the fees are not determined by income and profits. Other fees generally are not qualifying income for purposes of either gross income test. Any fees earned by a taxable REIT subsidiary will not be included for purposes of the gross income tests.

in connection with a lease of real property is greater than 15% of the total rent received under the lease, then the portion of rent attributable to the personal property will not qualify as rents from real property. Finally, for rents to qualify as “rents from real property” for purposes of the gross income tests, we are only allowed to provide services that are both usually or “customarily rendered” in connection with the rental of real property and not otherwise considered “rendered to the occupant.” We may, however, render services to our tenants through an “independent contractor” who is adequately compensated and from whom we do not derive revenue. We may also own a taxable REIT subsidiary which provides non-customary services to tenants without tainting our rental income from the related properties.

Even if a REIT furnishes or renders services that are non-customary with respect to a property, if the greater of (i) the amounts received or accrued, directly or indirectly, or deemed received by the REIT with respect to such services, or (ii) 150% of our direct cost in furnishing or rendering the services during a taxable year is not more than 1% of all amounts received or accrued, directly or indirectly by the REIT with respect to the property during the same taxable year, then only the amounts with respect to such non-customary services are not treated as rent for purposes of the REIT gross income tests.

Prohibited Transactions Tax. A REIT will incur a 100% tax on the net income derived from any sale or other disposition of property, other than foreclosure property, that the REIT holds primarily for sale to customers in the ordinary course of a trade or business. Whether a REIT holds an asset primarily for sale to customers in the ordinary course of a trade or business depends, however, on the facts and circumstances in effect from time to time, including those related to a particular asset. Nevertheless, we will attempt to conduct our operations so that no asset that we own will be treated as, or as having been, held for sale to customers, and that a sale of any such asset will not be treated as having been in the ordinary course of our business. We cannot assure you that we will comply with certain safe harbor provisions or that we will avoid owning property that may be characterized as property that we hold primarily for sale to customers in the ordinary course of a trade or business. The 100% tax will not apply to gains from the sale of property that is held through a TRS or other taxable corporation, although such income will be subject to tax in the hands of the corporation at regular corporate income tax rates.

Foreclosure Property. Foreclosure property is any real property, including interests in real property, and any personal property incident to such real property:

However, a REIT will not be considered to have foreclosed on a property where the REIT takes control of the property as a mortgagee-in-possession and cannot receive any profit or sustain any loss except as a creditor of the mortgagor.

Property generally ceases to be foreclosure property at the end of the third taxable year following the taxable year in which the REIT acquired the property, or longer if an extension is granted by the Secretary of the Treasury. This grace period terminates and foreclosure property ceases to be foreclosure property on the first day:

We will be subject to tax at the maximum corporate rate on any income from foreclosure property, other than income that otherwise would be qualifying income for purposes of the 75% gross income test, less expenses directly connected with the production of that income. However, income from foreclosure property, including gain from the sale of foreclosure property held for sale in the ordinary course of a trade or business, will qualify for purposes of the 75% and 95% gross income tests.

We may have the option to foreclose on mortgage loans when a borrower is in default. The foregoing rules could affect a decision by us to foreclose on a particular mortgage loan and could affect whether we choose to foreclose with regard to a particular mortgage loan.

Phantom income. Due to the nature of the assets in which we will invest, we may be required to recognize taxable income from certain assets in advance of our receipt of cash flow from or proceeds from disposition of such assets, and may be required to report taxable income that exceeds the economic income ultimately realized on such assets.

We may acquire debt instruments in the secondary market for less than their face amount. The amount of such discount generally will be treated as “market discount” for United States federal income tax purposes. Accrued market discount is reported as income when, and to the extent that, any payment of principal of the debt instrument is made, unless we elect to include accrued market discount in income as it accrues. Principal payments on certain loans are made monthly, and consequently accrued market discount may have to be included in income each month as if the debt instrument were assured of ultimately being collected in full. If we collect less on the debt instrument than our purchase price plus the market discount we had previously reported as income, we may not be able to benefit from any offsetting loss deductions.

We may agree to modify the terms of distressed and other loans we hold. These modifications may be considered “significant modifications” for United States federal income tax purposes that give rise to a deemed debt-for-debt exchange upon which we may recognize taxable income or gain without a corresponding receipt of cash.

Some of the debt securities that we acquire may have been issued with original issue discount. In general, we will be required to accrue original issue discount based on the constant yield to maturity of the debt securities, and to treat it as taxable income in accordance with applicable United States federal income tax rules even though such yield may exceed cash payments, if any, received on such debt instrument.

In addition, in the event that any debt instruments or debt securities acquired by us are delinquent as to mandatory principal and interest payments, or in the event payments with respect to a particular debt instrument are not made when due, we may nonetheless be required to continue to recognize the unpaid interest as taxable income. Similarly, we may be required to accrue interest income with respect to subordinated mortgage-backed securities at the stated rate regardless of whether corresponding cash payments are received.

Finally, we may be required under the terms of indebtedness that we incur to use cash received from interest payments to make principal payments on that indebtedness, with the effect of recognizing income but not having a corresponding amount of cash available for distribution to our stockholders.

excess of cash available for distribution. In that event, we may need to borrow funds or take other action to satisfy the REIT distribution requirements for the taxable year in which this “phantom income” is recognized. See “—Annual Distribution Requirements Applicable to REITs.”

At the close of each quarter of our taxable year, we must satisfy the following tests relating to the nature of our assets.

Securities, for the purposes of the asset tests, may include debt we hold from other issuers. However, debt we hold in an issuer that does not qualify for purposes of the 75% asset test will not be taken into account for purposes of the 10% value test if the debt securities meet the straight debt safe harbor. Debt will meet the “straight debt” safe harbor if the debt is a written unconditional promise to pay on demand or on a specified date a sum certain in money, the debt is not convertible, directly or indirectly, into stock, and the interest rate and the interest payment dates of the debt are not contingent on the profits, the borrower’s discretion or similar factors. In the case of an issuer that is a corporation or a partnership, securities that otherwise would be considered straight debt will not be so considered if we, and any of our “controlled taxable REIT subsidiaries” as defined in the Internal Revenue Code, hold any securities of the corporate or partnership issuer that (a) are not straight debt or

other excluded securities (prior to the application of this rule), and (b) have an aggregate value greater than 1% of the issuer’s outstanding securities (including, for the purposes of a partnership issuer, our interest as a partner in the partnership).

In addition, (i) a REIT’s interest as a partner in a partnership is not considered a security for purposes of applying the 10% value test; (ii) any debt instrument issued by a partnership (other than straight debt or any other excluded security) will not be considered a security issued by the partnership if at least 75% of the partnership’s gross income is derived from sources that would qualify for the 75% REIT gross income test; and (iii) any debt instrument issued by a partnership (other than straight debt or any other excluded security) will not be considered a security issued by the partnership to the extent of the REIT’s interest as a partner in the partnership.

We believe that substantially all of the mortgage-related assets and loans that we expect to hold will be qualifying assets for purposes of the 75% asset test. For purposes of these rules, however, if the outstanding principal balance of a mortgage loan exceeds the fair market value of the real property securing the loan, a portion of such loan likely will not be a qualifying real estate asset under the federal income tax laws. Although the law on the matter is not entirely clear, it appears that the non-qualifying portion of that mortgage loan will be equal to the portion of the loan amount that exceeds the value of the associated real property that is security for that loan. Debt securities issued by other REITs or C corporations that are not secured by mortgages on real property will not be qualifying assets for purposes of the 75% asset test.

We believe that any stock that we will acquire in other REITs will be a qualifying asset for purposes of the 75% asset test. However, if a REIT in which we own stock fails to qualify as a REIT in any year, the stock in such REIT will not be a qualifying asset for purposes of the 75% asset test. Instead, we would be subject to the second, third, fourth, and fifth assets tests described above with respect to our investment in such a disqualified REIT. We will also be subject to those assets tests with respect to our investments in any non-REIT C corporations for which we do not make a taxable REIT subsidiary election.

We have and intend to enter into repurchase agreements under which we will nominally sell certain of our assets to a counterparty and simultaneously enter into an agreement to repurchase the sold assets. We believe that we will be treated for United States federal income tax purposes as the owner of the assets that are the subject of any such agreements notwithstanding that we may transfer record ownership of the assets to the counterparty during the term of the agreement. It is possible, however, that the IRS could assert that we did not own the assets during the term of the repurchase agreement, in which case we could fail to qualify as a REIT.

We will monitor the status of our assets for purposes of the various asset tests and will seek to manage our portfolio to comply at all times with such tests. There can be no assurances, however, that we will be successful in this effort. In this regard, to determine our compliance with these requirements, we will need to estimate the value of the real estate securing our mortgage loans at various times. In addition, we will be required to value our investment in our other assets to ensure compliance with the asset tests. Although we will seek to be prudent in making these estimates, there can be no assurances that the IRS may not disagree with these determinations and assert that a different value is applicable, in which case we may not satisfy the 75% and the other asset tests.

We will not lose our REIT status for a de minimis failure to meet the 5% or 10% asset requirements if the failure is due to ownership of assets the total value of which does not exceed the lesser of 1% of the total value of our assets or $10 million. If we fail to satisfy any of the asset requirements for a particular tax quarter, we may still qualify as a REIT if we (1) identify the failure on a separate schedule, (2) the failure is due to reasonable cause and not willful neglect, (3) the assets causing the failure are disposed of within six months of the last day of the quarter in which the failure occurred and (4) we pay a tax computed as the greater of either $50,000 or the net income generated by the assets causing the failure multiplied by the highest tax rate under section 11.

our assets. However, an acquisition of property by a REIT requires the REIT to revalue all of its assets. If the failure to satisfy the asset tests results from an increase in the value of our assets after the acquisition of securities or other property during a quarter, the failure can be cured by eliminating the discrepancy within 30 days after the close of that quarter. We intend to maintain adequate records of the value of our assets to ensure compliance with the asset tests and to take any available action within 30 days after the close of any quarter as may be required to cure any noncompliance with the asset tests. We cannot ensure that these steps always will be successful. If we fail to cure the noncompliance with the asset tests within this 30-day period, we could fail to qualify as a REIT.

We currently believe that the loans, securities and other assets that we expect to hold will satisfy the foregoing asset test requirements. However, no independent appraisals will be obtained to support our conclusions as to the value of our assets and securities, or in many cases, the real estate collateral for the mortgage loans that we hold. Moreover, values of some assets may not be susceptible to a precise determination. As a result, there can be no assurance that the IRS will not contend that our interest in securities and other assets will not cause a violation of the asset tests applicable to REITs.

To qualify as a REIT, we generally must distribute dividends (other than capital gain dividends) to our stockholders in an amount at least equal to:

Distributions generally must be made during the taxable year to which they relate. Distributions may be made in the following year in two circumstances. First, if we declare a dividend in October, November or December of any year with a record date in one of these months and pay the dividend on or before January 31 of the following year, we will be treated as having paid the dividend on December 31 of the year in which the dividend was declared. Second, distributions may be made in the following year if the dividends are declared before we timely file our tax return for the year and if made before the first regular dividend payment made after such declaration. These distributions are taxable to our stockholders in the year in which paid, even though the distributions relate to our prior taxable year for purposes of the 90% distribution requirement. To the extent that we do not distribute all of our net capital gain or we distribute at least 90%, but less than 100% of our REIT taxable income, as adjusted, we will be subject to tax on the undistributed amount at regular corporate tax rates.

In order for distributions to be counted as satisfying the annual distribution requirements for REITs, and to provide us with a REIT-level tax deduction, the distributions must not be “preferential dividends.” A dividend is not a preferential dividend if the distribution is (1) pro-rata among all outstanding shares of stock within a particular class, and (2) in accordance with the preferences among different classes of stock as set forth in our organizational documents.

If we fail to distribute during a calendar year (or, in the case of distributions with declaration and record dates falling in the last three months of the calendar year, by the end of January following such calendar year) at least the sum of (i) 85% of our ordinary income for such year, (ii) 95% of our capital gain net income for such year and (iii) any undistributed taxable income from prior years, we will be subject to a 4% excise tax on the excess of such required distribution over the sum of (x) the amounts actually distributed (taking into account excess distributions from prior years) and (y) the amounts of income retained on which we have paid corporate income tax.

We may elect to retain rather than distribute all or a portion of our net capital gains and pay the tax on the gains. In that case, we may elect to have our stockholders include their proportionate share of the undistributed net capital gains in income as long-term capital gains and receive a credit for their share of the tax paid by us. For purposes of the 4% excise tax described above, any retained amounts for which we elect this treatment would be treated as having been distributed.

We intend to make timely distributions sufficient to satisfy the distribution requirements. It is possible that, from time to time, we may not have sufficient cash to meet the distribution requirements due to timing differences between the actual receipt of cash and the inclusion of items of income by us for United States federal income tax purposes. Other potential sources of non-cash taxable income include (i) loans and securities that are financed through loan or securitization structures that require some or all of the available interest income from these assets to be used to repay principal on these borrowings, (ii) distressed loans on which we may be required to accrue interest or discount income even though the borrower is unable to make current or past due debt service payments; and, (iii) loans or mortgage-backed securities held by us as assets that are issued at a discount and require the accrual of taxable income in advance of the receipt of the related cash flow. In the event that such timing differences occur, and in other circumstances, it may be necessary in order to satisfy the distribution requirements to arrange for short-term, or possibly long-term, borrowings, or to pay the dividends in the form of taxable in-kind distributions of property (including, for example, our own debt securities).

Although several types of non-cash income are excluded in determining the annual distribution requirement, we will incur corporate income tax and the 4% nondeductible excise tax with respect to those non-cash income items if we do not distribute those items on a current basis. As a result of the foregoing, we may not have sufficient cash to distribute all of our taxable income and thereby avoid corporate income tax and the excise tax imposed on certain undistributed income. In such a situation, we may need to borrow funds or issue additional common stock or preferred stock.

Under some circumstances, we may be able to rectify a failure to meet the distribution requirement for a year by paying deficiency dividends to stockholders in a later year, which may be included in our deduction for dividends paid for the earlier year. Thus, we may be able to avoid being taxed on amounts distributed as deficiency dividends. However, we will be required to pay interest based upon the amount of any deduction taken for deficiency dividends.

We are required to comply with applicable record keeping requirements. Failure to comply could result in monetary fines. For example, we must request on an annual basis information from our stockholders designed to disclose the actual ownership of our outstanding class A common stock.

If we fail to satisfy one or more requirements of REIT qualification, other than the income tests or asset requirements, then we may still retain REIT qualification if the failure is due to reasonable cause and not willful neglect, and we pay a penalty of $50,000 for each failure.

If we fail to qualify for taxation as a REIT in any taxable year and the relief provisions do not apply, we will be subject to tax, including any applicable alternative minimum tax, on our taxable income at regular corporate rates. This would significantly reduce both our cash available for distribution to our stockholders and our earnings. If we fail to qualify as a REIT, we will not be required to make any distributions to stockholders and any distributions that are made will not be deductible by us. Moreover, all distributions to stockholders would be taxable as dividends to the extent of our current and accumulated earnings and profits, whether or not attributable to capital gains of ours. Subject to certain limitations of the Internal Revenue Code, corporate distributees may be eligible for the dividends received deduction with respect to those distributions, and individual, trust and estate

distributees may be eligible for reduced income tax rates on such dividends. Unless we are entitled to relief under specific statutory provisions, we also will be disqualified from taxation as a REIT for the four taxable years following the year during which qualification was lost.

United States Holder. As used in the remainder of this discussion, the term “United States holder” means a beneficial owner of our class A common stock that is for United States federal income tax purposes:

If a partnership (or an entity treated as a partnership for United States federal income tax purposes) holds our class A common stock, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding class A common stock, you should consult your advisors. A “non-United States holder” is a beneficial owner of our class A common stock that is neither a United States holder nor a partnership (or an entity treated as a partnership for United States federal income tax purposes).

Distributions Generally. As long as we qualify as a REIT, distributions made to taxable United States holders of our class A common stock out of our current or accumulated earnings and profits that are not designated as capital gain dividends or “qualified dividend income” will be taken into account by them on the day such distributions are actually or constructively received as ordinary income taxable at ordinary income tax rates and will not qualify for the reduced capital gains rates that currently generally apply to distributions by non-REIT C corporations to certain non-corporate United States holders. In determining the extent to which a distribution constitutes a dividend for tax purposes, our earnings and profits will be allocated first to distributions with respect to our preferred stock, if any, and then to our class A common stock. Corporate stockholders will not be eligible for the dividends received deduction with respect to these distributions.

Distributions in excess of both current and accumulated earnings and profits will not be taxable to a United States holder to the extent that the distributions do not exceed the adjusted basis of the holder’s stock. Rather, such distributions will reduce the adjusted basis of the stock. To the extent that distributions exceed the adjusted basis of a United States holder’s stock, the distributions will be taxable as capital gains, assuming the stock is held as a capital asset in the hands of the United States holder.

Distributions will generally be taxable, if at all, in the year of the distribution. However, if we declare a dividend in October, November or December of any year with a record date in one of these months and pay the dividend on or before January 31 of the following year, we will be treated as having paid the dividend, and the stockholder will be treated as having received the dividend, on December 31 of the year in which the dividend was declared.

regardless of our earnings and profits. As a result, United States holders may be required to treat certain distributions that would otherwise result in a tax-free return of capital as taxable dividends.

Capital Gain Dividends. We may elect to designate distributions of our net capital gain as “capital gain dividends.” Capital gain dividends are taxed to United States holders of our stock as gain from the sale or exchange of a capital asset held for more than one year. This tax treatment applies regardless of the period during which the stockholders have held their stock. If we designate any portion of a dividend as a capital gain dividend, the amount that will be taxable to the stockholder as capital gain will be indicated to United States holders on IRS Form 1099-DIV. Corporate stockholders, however, may be required to treat up to 20% of capital gain dividends as ordinary income. Capital gain dividends are not eligible for the dividends-received deduction for corporations.

Instead of paying capital gain dividends, we may elect to require stockholders to include our undistributed net capital gains in their income. If we make such an election, United States holders (i) will include in their income as long-term capital gains their proportionate share of such undistributed capital gains and (ii) will be deemed to have paid their proportionate share of the tax paid by us on such undistributed capital gains and thereby receive a credit or refund for such amount. A United States holder of our stock will increase the basis in its stock by the difference between the amount of capital gain included in its income and the amount of tax it is deemed to have paid. Our earnings and profits will be adjusted appropriately.

We must classify portions of our designated capital gain dividend into the following categories:

We must determine the maximum amounts that we may designate as 20% and 25% capital gain dividends by performing the computation required by the Internal Revenue Code as if the REIT were an individual whose ordinary income were subject to a marginal tax rate of at least 28%. The IRS currently requires that distributions made to different classes of stock be composed proportionately of dividends of a particular type.

Passive Activity Loss and Investment Interest Limitation. Distributions and gain from the disposition of our class A common stock will not be treated as passive activity income, and therefore United States holders will not be able to apply any “passive activity losses” against such income. Dividends paid by us, to the extent they do not constitute a return of capital, will generally be treated as investment income for purposes of the investment income limitation on the deduction of the investment interest.

Qualified Dividend Income. Distributions that are treated as dividends may be taxed at capital gains rates, rather than ordinary income rates, if they are distributed to an individual, trust or estate, are properly designated by us as qualified dividend income and certain other requirements are satisfied. Dividends are eligible to be designated by us as qualified dividend income up to an amount equal to the sum of the qualified dividend income received by us during the year of the distribution from other C corporations such as taxable REIT subsidiaries, our “undistributed” REIT taxable income from the immediately preceding year, and any income attributable to the sale of a built-in gain asset from the immediately preceding year (reduced by any federal income taxes that we paid with respect to such REIT taxable income and built-in gain).

Dividends that we receive will be treated as qualified dividend income to us if certain criteria are met. The dividends must be received from a domestic corporation (other than a REIT or a regulated investment company) or a qualifying foreign corporation. A foreign corporation generally will be a qualifying foreign corporation if it is incorporated in a possession of the United States, the corporation is eligible for benefits of an income tax treaty with the United States which the Secretary of Treasury determines is satisfactory, or the stock on which the dividend is paid is readily tradable on an established securities market in the United States. However, if a foreign

corporation is a foreign personal holding company, a foreign investment company or a passive foreign investment company, then it will not be treated as a qualifying foreign corporation and the dividends we receive from such an entity would not constitute qualified dividend income.

Furthermore, certain exceptions and special rules apply to determine whether dividends may be treated as qualified dividend income to us. These rules include certain holding requirements that we would have to satisfy with respect to the stock on which the dividend is paid, and special rules with regard to dividends received from regulated investment companies and other REITs.

In addition, even if we designate certain dividends as qualified dividend income to our stockholders, the stockholder will have to meet certain other requirements for the dividend to qualify for taxation at capital gains rates. For example, the stockholder will only be eligible to treat the dividend as qualifying dividend income if the stockholder is taxed at individual rates and meets certain holding requirements. In general, in order to treat a particular dividend as qualified dividend income, a stockholder will be required to hold our stock for more than 60 days during the 121-day period beginning on the date which is 60 days before the date on which the stock becomes ex-dividend. A longer holding period may apply to preferred dividends that are attributable to a period or periods aggregating in excess of 366 days.

Other Tax Considerations. United States holders of our stock may not include in their individual income tax returns any of our net operating losses or capital losses. Our operating or capital losses would be carried over by us for potential offset against future income, subject to applicable limitations.

Sales of Our Class A Common Stock. Upon any taxable sale or other disposition of our class A common stock, a United States holder of our class A common stock will recognize gain or loss for federal income tax purposes on the disposition of our class A common stock in an amount equal to the difference between:

Gain or loss will be capital gain or loss if the class A common stock has been held by the United States holder as a capital asset. The applicable tax rate will depend on the holder’s holding period in the asset (generally, if an asset has been held for more than one year it will produce long-term capital gain) and the holder’s tax bracket.

In general, any loss upon a sale or exchange of our class A common stock by a United States holder who has held such stock for six months or less (after applying certain holding period rules) will be treated as a long-term capital loss, but only to the extent of distributions from us received by such United States holder that are required to be treated by such United States holder as long-term capital gains.

Medicare Tax. Certain United States holders, including individuals and estates and trusts, are subject to an additional 3.8% Medicare tax on all or a portion of their “net investment income,” which includes net gain from a sale or exchange of class A common stock and income from dividends paid on class A common stock. United States holders are urged to consult their own tax advisors regarding the Medicare tax.

The rules governing United States federal income taxation of non-United States holders are complex. This section is only a summary of such rules. We urge non-United States holders to consult their own tax advisors to determine the impact of federal, state and local income tax laws on ownership of the common stock, including any reporting requirements.

Distributions. Distributions by us to a non-United States holder of our class A common stock that are neither attributable to gain from sales or exchanges by us of “United States real property interests” nor designated by us as capital gains dividends will be treated as dividends of ordinary income to the extent that they are made out of our current or accumulated earnings and profits. These distributions generally will be subject to United States federal income tax on a gross basis at a rate of 30%, or a lower rate as may be specified under an applicable income tax treaty, unless the dividends are treated as effectively connected with the conduct by the non-United States holder of a trade or business within the United States. Under some treaties, however, lower rates generally applicable to dividends do not apply to dividends from REITs. Further, reduced treaty rates are not available to the extent the income allocated to the non-United States stockholder is excess inclusion income. Excess inclusion income will generally be allocated to our stockholders to the extent we have “excess inclusion income” that exceeds our undistributed REIT taxable income in a particular year. See “—Our Taxation as a REIT—Taxable Mortgage Pools and REMICs.” Dividends that are effectively connected with the non-United States holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, are attributable to a United States permanent establishment) will be subject to tax on a net basis, that is, after allowance for deductions, at graduated rates, in the same manner as United States holders are taxed with respect to these dividends, and are generally not subject to withholding. Applicable certification and disclosure requirements must be satisfied to be exempt from withholding under the effectively connected income exception. Any dividends received by a corporate non-United States holder that is engaged in a trade or business within the United States also may be subject to an additional branch profits tax at a 30% rate, or lower applicable treaty rate.

A non-United States holder of our class A common stock who wishes to claim the benefit of an applicable treaty rate and avoid backup withholding, as discussed below, for our ordinary dividends will be required (a) to complete the applicable Internal Revenue Service Form W-8 and certify under penalty of perjury that such holder is not a United States person as defined under the Internal Revenue Code and is eligible for treaty benefits or (b) if our class A common stock is held through certain foreign intermediaries, to satisfy the relevant certification requirements of applicable Treasury regulations. Special certification and other requirements apply to certain non-United States holders that are pass-through entities rather than corporations or individuals.

A non-United States holder of our class A common stock eligible for a reduced rate of United States withholding tax pursuant to an income tax treaty may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS.

Distributions in excess of our current or accumulated earnings and profits that do not exceed the adjusted basis of the non-United States holder in its class A common stock will reduce the non-United States holder’s adjusted basis in its class A common stock and will not be subject to United States federal income tax. Distributions in excess of current and accumulated earnings and profits that do exceed the adjusted basis of the non-United States holder in its class A common stock will be treated as gain from the sale of its stock, the tax treatment of which is described below. See “—Taxation of Non-United States Holders of Our Class A Common Stock—Sales of Our Class A Common Stock.” Because we generally cannot determine at the time we make a distribution whether or not the distribution will exceed our current and accumulated earnings and profits, we normally will withhold tax on the entire amount of any distribution at the same rate as we would withhold on a dividend.

We would be required to withhold at least 10% of any distribution to a non-United States holder in excess of our current and accumulated earnings and profits if our class A common stock constitutes a United States real property interest with respect to such non-United States holder, as described below under “—Taxation of Non-United States Holders of Our Class A Common Stock—Sales of Our Class A Common Stock.” This withholding would apply even if a lower treaty rate applies or the non-United States holder is not liable for tax on the receipt of that distribution. However, a non-United States holder may seek a refund of these amounts from the IRS if the non-United States holder’s United States tax liability with respect to the distribution is less than the amount withheld.

Distributions to a non-United States holder that are designated by us at the time of the distribution as capital gain dividends, other than those arising from the disposition of a United States real property interest, generally should not be subject to United States federal income taxation unless:

Under the Foreign Investment in Real Property Tax Act of 1980, which is referred to as “FIRPTA,” distributions to a non-United States holder that are attributable to gain from sales or exchanges by us of United States real property interests, whether or not designated as a capital gain dividend, will cause the non-United States holder to be treated as recognizing gain that is income effectively connected with a United States trade or business. Non-United States holders will be taxed on this gain at the same rates applicable to United States holders, subject to a special alternative minimum tax in the case of nonresident alien individuals. Also, this gain may be subject to a 30% (or lower applicable treaty rate) branch profits tax in the hands of a non-United States holder that is a corporation. The term “United States real property interests” generally does not include mortgage loans or mortgage-backed securities. As a result, we do not anticipate that we will generate material amounts of gain that would be subject to FIRPTA.

We will be required to withhold and remit to the IRS 35% of any distributions to non-United States holders that are designated as capital gain dividends, or, if greater, 35% of a distribution that could have been designated as a capital gain dividend, whether or not attributable to sales of United States real property interests. Distributions can be designated as capital gains to the extent of our net capital gain for the taxable year of the distribution. The amount withheld, which for individual non-United States holders may exceed the actual tax liability, is creditable against the non-United States holder’s United States federal income tax liability.

However, the 35% withholding tax will not apply to any capital gain dividend with respect to any class of our stock which is regularly traded on an established securities market located in the United States if the non-United States stockholder did not own more than 5% of such class of stock at any time during the one-year period ending on the date of such dividend. Instead, any capital gain dividend will be treated as a distribution subject to the rules discussed above under “—Taxation of Non-United States Stockholders of Our Class A Common Stock—Distributions.” Also, the branch profits tax will not apply to such a distribution.

Although the law is not clear on the matter, it appears that amounts we designate as undistributed capital gains in respect of the stock held by United States holders generally should be treated with respect to non-United States holders in the same manner as actual distributions by us of capital gain dividends. Under that approach, the non-United States holders would be able to offset as a credit against their United States federal income tax liability resulting therefrom their proportionate share of the tax paid by us on the undistributed capital gains, and to receive from the IRS a refund to the extent that their proportionate share of this tax paid by us were to exceed their actual United States federal income tax liability.

Sales of Our Class A Common Stock. Gain recognized by a non-United States holder upon the sale or exchange of our stock generally would not be subject to United States taxation unless:

Our class A common stock will not constitute a United States real property interest if we either are not a United States real property holding corporation or we are a domestically-controlled REIT. Whether we are a United States real property holding corporation will depend upon whether the fair market value of United States real property interests owned by us equals or exceeds 50% of the fair market value of these interests, any interests in real estate outside of the United States, and our other trade and business assets. Because United States real property interests do not generally include mortgage loans or mortgage-backed securities, we do not expect to be a United States real property holding corporation although we cannot guarantee that we will not become one at a later date. We will be a domestically-controlled REIT if, at all times during a specified testing period, less than 50% in value of our stock is held directly or indirectly by non-United States holders.

Because our stock is publicly traded, no assurance can be given that we are or will be a domestically-controlled REIT. Even if we were a United States real property holding corporation and were not a domestically-controlled REIT, a sale of class A common stock by a non-United States holder would nevertheless not be subject to taxation under FIRPTA as a sale of a United States real property interest if:

Even if our class A common stock were not regularly traded on an established securities market, a sale of class A common stock by a non-United States holder would not be subject to taxation under FIRPTA as a sale of a United States real property interest if such non-United States holder’s class A common stock had a fair market value on the date of acquisition that was equal to or less than 5% of our regularly traded class of stock, if any, with the lowest fair market value. For purposes of this test, if a non-United States holder acquires shares of class A common stock and subsequently acquired additional shares of class A common stock at a later date, then all such shares of class A common stock would be aggregated and valued as of the date of the subsequent acquisition.

referred to as UBTI, to a tax-exempt holder. Similarly, income from the sale of our class A common stock will not constitute UBTI unless the tax-exempt holder has held its class A common stock as debt-financed property within the meaning of the Internal Revenue Code or has used the class A common stock in a trade or business. To the extent, however, that we, or a part of us, or a disregarded subsidiary of ours, is a taxable mortgage pool, a portion of the dividends paid to a tax-exempt stockholder that is allocable to excess inclusion income may be subject to tax as UBTI. Excess inclusion income will generally be allocated to our stockholders to the extent we have excess inclusion income that exceeds our undistributed REIT taxable income in a particular year. See “—Our Taxation as a REIT—Taxable Mortgage Pools and REMICs.”

Further, for a tax-exempt holder that is a social club, voluntary employee benefit association, supplemental unemployment benefit trust or qualified group legal services plan exempt from federal income taxation under Sections 501(c)(7), (c)(9), (c)(17) and (c)(20) of the Internal Revenue Code, respectively, or a single parent title-holding corporation exempt under Section 501(c)(2) the income of which is payable to any of the aforementioned tax-exempt organizations, income from an investment in our class A common stock will constitute UBTI unless the organization properly sets aside or reserves such amounts for purposes specified in the Internal Revenue Code. These tax-exempt holders should consult their own tax advisors concerning these “set aside” and reserve requirements.

Notwithstanding the above, however, a portion of the dividends paid by a “pension-held REIT” are treated as UBTI as to any trust which is described in Section 401(a) of the Internal Revenue Code, is tax-exempt under Section 501(a) of the Internal Revenue Code, and holds more than 10%, by value, of the interests in the REIT. Tax-exempt pension funds that are described in Section 401(a) of the Internal Revenue Code are referred to below as “pension trusts.”

The percentage of any REIT dividend from a “pension-held REIT” that is treated as UBTI is equal to the ratio of the UBTI earned by the REIT, treating the REIT as if it were a pension trust and therefore subject to tax on UBTI, to the total gross income of the REIT. An exception applies where the percentage is less than 5% for any year, in which case none of the dividends would be treated as UBTI. The provisions requiring pension trusts to treat a portion of REIT distributions as UBTI will not apply if the REIT is not a “pension-held REIT” (for example, if the REIT is able to satisfy the “not closely held requirement” without relying on the “look through” exception with respect to pension trusts).

Non-United States Holders of Our Class A Common Stock. We must report annually to the IRS and to each non-United States holder the amount of dividends and interest paid to such holder and the tax withheld with respect to such dividends and interest, regardless of whether withholding was required. Copies of the information returns reporting such dividends and interest and withholding may also be made available to the tax authorities in the country in which the non-United States holder resides under the provisions of an applicable income tax treaty.

A non-United States holder will be subject to backup withholding for dividends paid to such holder unless such holder certifies under penalty of perjury that it is a non-United States holder (and the payor does not have actual knowledge or reason to know that such holder is a United States person as defined under the Internal Revenue Code), or such holder otherwise establishes an exemption.

Information reporting and, depending on the circumstances, backup withholding will apply to the proceeds of a sale of our class A common stock within the United States or conducted through certain United States-related financial intermediaries, unless the beneficial owner certifies under penalty of perjury that it is a non-United States holder (and the payor does not have actual knowledge or reason to know that the beneficial owner is a United States person as defined under the Internal Revenue Code), or such owner otherwise establishes an exemption.

Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a non-United States holder’s United States federal income tax liability provided the required information is timely furnished to the IRS.

We and our stockholders may be subject to state or local taxation in various state or local jurisdictions, including those in which we or they transact business or reside. Our state and local tax treatment and that of our stockholders may not conform to the federal income tax treatment discussed above. Consequently, prospective stockholders should consult their own tax advisors regarding the effect of state and local tax laws on an investment in our class A common stock.

If a stockholder recognizes a loss with respect to stock of $2 million or more for an individual stockholder or $10 million or more for a corporate stockholder, the stockholder must file a disclosure statement with the IRS on Form 8886. Direct stockholders of portfolio securities are in many cases exempt from this reporting requirement, but stockholders of a REIT currently are not excepted. The fact that a loss is reportable under these regulations does not affect the legal determination of whether the taxpayer’s treatment of the loss is proper. Stockholders should consult their tax advisors to determine the applicability of these regulations in light of their individual circumstances.

Under Sections 1471 through 1474 of the Internal Revenue Code (such Sections commonly referred to as “FATCA”), a 30% United States federal withholding tax may apply to any ordinary dividends and other distributions that we pay and, beginning January 1, 2017, the gross proceeds from certain capital gain dividends or the disposition of our class A common stock, in each case paid to (i) a “foreign financial institution” (as specifically defined in the Internal Revenue Code), whether such foreign financial institution is the beneficial owner or an intermediary, unless such foreign financial institution agrees to verify, report and disclose its United States “account” holders (as specifically defined in the Internal Revenue Code) and meets certain other specified requirements or (ii) a non-financial foreign entity, whether such non-financial foreign entity is the beneficial owner or an intermediary, unless such entity provides a certification that the beneficial owner of the

payment does not have any substantial United States owners or provides the name, address and taxpayer identification number of each such substantial United States owner and certain other specified requirements are met. In certain cases, the relevant foreign financial institution or non-financial foreign entity may qualify for an exemption from, or be deemed to be in compliance with, these rules. In addition, foreign financial institutions located in jurisdictions that have an intergovernmental agreement with the United States governing FATCA may be subject to different rules. Non-United States holders should consult their own tax advisers regarding FATCA and whether it may be relevant to their ownership and disposition of our class A common stock.

The validity of the shares of class A common stock offered hereby will be passed upon for us by Venable LLP, Baltimore, Maryland. Certain other legal matters in connection with the offering of the shares of class A common stock will be passed upon for us by Simpson Thacher & Bartlett LLP, New York, New York. An investment vehicle comprised of several partners of Simpson Thacher & Bartlett LLP, members of their families, related persons and others own interest representing less than 1% of the capital commitments of funds affiliated with Blackstone. Certain legal matters related to this offering will be passed upon for the underwriters by Paul Hastings LLP, New York, New York. Martin L. Edelman, who serves as one of our directors, is Of Counsel to Paul Hastings LLP. Paul Hastings LLP has from time to time represented us in connection with other matters.

The consolidated financial statements of Blackstone Mortgage Trust, Inc. as of December 31, 2014 and 2013 and for the years then ended (including the schedule appearing therein), and the effectiveness of Blackstone Mortgage Trust’s internal control over financial reporting as of December 31, 2014 have been audited by Deloitte & Touche LLP, independent registered public accounting firm, as set forth in their report thereon included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

The consolidated financial statements of Blackstone Mortgage Trust, Inc. (formally Capital Trust, Inc.) for the year ended December 31, 2012 (including the schedule appearing therein) have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any materials we have filed with the SEC at the SEC’s Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. The SEC also maintains a web site at www.sec.gov that contains reports, proxy and information statements and other information concerning issuers that file electronically with the SEC, including us. Our class A common stock is listed and traded on the NYSE. We also maintain an internet site at www.bxmt.com that contains information concerning us. The information contained on our website is not part of, or incorporated by reference into, this prospectus supplement or the accompanying prospectus.

This prospectus supplement and the accompanying prospectus are only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act and therefore omit some of the information contained in the registration statement. We have also filed exhibits to the registration statement which are excluded from this prospectus supplement and the accompanying prospectus, and you should refer to the applicable exhibit for a complete description of any statement referring to any contract or other document. You may inspect or obtain a copy of the registration statement, including the exhibits, as described in the previous paragraph.

SEC rules allow us to incorporate by reference information into this prospectus supplement and the accompanying prospectus. This means that we can disclose important information to you by referring you to another document. Any information referred to in this way is considered part of this prospectus supplement and the accompanying prospectus from the date we file that document. We incorporate by reference into this prospectus supplement and the accompanying prospectus the following documents or information filed with the SEC (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules):

All documents subsequently filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus supplement and prior to the termination of the offering are deemed incorporated by reference into this prospectus supplement and a part hereof from the date of filing of those documents, and will automatically update and, where applicable, supersede any information contained in this prospectus supplement and the accompanying prospectus or incorporated by reference herein and therein. Notwithstanding the foregoing, with the exception of information under Item 7.01 of our Current Report on Form 8-K filed with the SEC on April 17, 2015 which is incorporated herein by reference, information furnished under Items 2.02 and 7.01 of our current reports on Form 8-K, including the related exhibits, is not incorporated by reference in this prospectus supplement and the accompanying prospectus. Any statement contained in any document incorporated by reference shall be deemed to be amended, modified or superseded for the purposes of this prospectus supplement and the accompanying prospectus to the extent that a statement contained in this prospectus supplement and the accompanying prospectus or a later document that is or is considered to be incorporated by reference herein amends, modifies or supersedes such statement. Any statements so amended, modified or superseded shall not be deemed to constitute a part of this prospectus supplement and the accompanying prospectus, except as so amended, modified or superseded.

We will provide without charge to each person to whom this prospectus supplement and the accompanying prospectus is delivered, upon written or oral request of such person, a copy of any or all of the documents referred to above which have been or may be incorporated by reference into this prospectus supplement and the accompanying prospectus. Requests for such documents should be directed to:

Blackstone Mortgage Trust, Inc. 345 Park Avenue, 42nd Floor New York, New York 10154 Attention: Investor Relations Telephone: (212) 655-0220

Class A Common Stock, Preferred Stock, Depositary Shares, Debt Securities, Warrants, Subscription Rights, Purchase Contracts and Units

We and any selling securityholders may from time to time offer and sell, in one or more series or classes, separately or together, the following securities:

We will offer our securities in amounts, at prices and on terms to be determined at the time we offer those securities. We will provide the specific terms of these securities in supplements to this prospectus when we offer these securities.

We are organized and conduct our operations so as to qualify as a real estate investment trust, or “REIT,” for federal income tax purposes. The specific terms of the securities may include limitations on actual, beneficial or constructive ownership and restrictions on transfer of the securities that may be appropriate to, among other purposes, preserve our status as a REIT.

The securities may be offered on a delayed or continuous basis directly by us and/or selling securityholders, through agents, underwriters or dealers as designated from time to time, through a combination of these methods or any other method as provided in the applicable prospectus supplement. You should read this prospectus and any applicable prospectus supplement carefully before you invest.

Our class A common stock is listed for trading on the New York Stock Exchange, or “NYSE,” under the symbol “BXMT”. On July 25, 2013, the last reported sale price of our class A common stock on the NYSE was $25.75 per share.

Investing in our securities involves risks. Before buying our securities, you should refer to the risk factors included in our periodic reports, in prospectus supplements relating to specific offerings and in other information that we file with the Securities and Exchange Commission. See “Risk Factors” on page 3.

None of the Securities and Exchange Commission, any state securities commission, or any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

You should rely only on the information contained in or incorporated by reference into this prospectus, any applicable prospectus supplement or any applicable free writing prospectus. We have not authorized anyone to provide you with information different from that contained in or incorporated by reference into this prospectus, any applicable prospectus supplement or any applicable free writing prospectus. You should assume that the information appearing in this prospectus, any applicable prospectus supplement, any applicable free writing prospectus or the documents incorporated by reference herein or therein is accurate only as of the respective dates of such documents or on the date or dates which are specified in such documents. Our business, financial condition, results of operation and prospects may have changed since those dates.

This prospectus is part of an automatic “shelf” registration statement that we filed with the Securities and Exchange Commission, or “SEC,” as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, or the “Securities Act,” utilizing a “shelf” registration process. By using this shelf registration process, we and/or any selling securityholders may sell any of our class A common stock, preferred stock, debt securities, depositary shares, subscription rights, units and warrants to purchase debt or equity securities described in this prospectus, from time to time in one or more offerings. This prospectus only provides you with a general description of the securities we may offer and such description is not meant to be a complete description of each security. Each time we or any selling securityholders sell securities, we will provide a prospectus supplement that will contain specific information about the terms of the offering and the securities being offered and information regarding the selling securityholders, if any. The prospectus supplement or a free writing prospectus may also add to, update or change information contained in this prospectus. If there is any inconsistency between information in this prospectus and any prospectus supplement or free writing prospectus, you should rely on the information in the prospectus supplement or free writing prospectus. Before purchasing any securities, you should carefully read both this prospectus and any supplement or free writing prospectus, together with additional information described under the heading “Where You Can Find More Information.”

Unless the context otherwise indicates, references in this prospectus to the terms “company,” “we,” “us,” “our,” and “Blackstone Mortgage Trust” refer to Blackstone Mortgage Trust, Inc., a Maryland corporation; “Manager” refers to BXMT Advisors L.L.C., a Delaware limited liability company, our external manager; and “Blackstone” refers to The Blackstone Group L.P., a Delaware limited partnership, and its subsidiaries.

We are a real estate finance company that focuses primarily on originating mortgage loans backed by commercial real estate assets. Our business plan is to create the premier global commercial real estate lending platform and to originate, acquire and manage commercial real estate loans and securities and other commercial real estate-related debt instruments. While the commercial real estate debt markets are complex and continually evolving, we believe they offer compelling opportunities when approached with the institutional capabilities and expertise of our Manager, an affiliate of Blackstone, one of the world’s leading investment and advisory firms. Our investment objective is to preserve and protect our capital while producing attractive risk-adjusted returns primarily through dividends generated from current income on our portfolio. We conduct our operations as a REIT for federal income tax purposes. Our class A common stock is traded on the NYSE, under the symbol “BXMT”.

Our principal executive offices are located at 345 Park Avenue, 42nd Floor, New York, New York 10154, and our telephone number is (212) 655-0220. Our web address is www.blackstonemortgagetrust.com. The information on, or otherwise accessible through, our website does not constitute a part of this prospectus.

Before you invest in any of our securities, in addition to the other information in this prospectus and the applicable prospectus supplement, you should carefully read and consider the risk factors under the heading “Risk Factors” contained in Part I, Item 1A in our most recent Annual Report on Form 10-K as well as any risk factors contained in our subsequent Quarterly Reports on Form 10-Q, which are incorporated by reference into this prospectus and the applicable prospectus supplement, as the same may be updated from time to time by our future filings under the Exchange Act of 1934, as amended, or the “Exchange Act.” Each of the risks described in these documents could materially and adversely affect our business, financial condition, results of operations and prospects, and could result in a partial or complete loss of your investment.

This prospectus, including information incorporated by reference herein, as well as any other oral or written statements made in press releases or otherwise by us or on our behalf, may contain forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act, which involve certain risks and uncertainties. Forward-looking statements may describe our future operations, business plans, business and investment strategies and portfolio management and the performance of our investments and our investment management business. Forward-looking statements predict or describe our future operations, business plans, business and investment strategies and portfolio management and the performance of our investments and our investment management business. These forward-looking statements are identified by their use of such terms and phrases as “intend,” “goal,” “estimate,” “expect,” “project,” “projections,” “plans,” “seeks,” “anticipates,” “should,” “could,” “may,” “designed to,” “foreseeable future,” “believe,” and “scheduled” and similar expressions. Our actual results or outcomes may differ materially from those anticipated. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date the statement was made. We assume no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Although we believe that the expectations reflected in these forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. We caution you not to place undue reliance on these forward-looking statements. All written and oral forward-looking statements attributable to us or persons acting on our behalf are qualified in their entirety by these cautionary statements. Moreover, unless we are required by law to update these statements, we will not necessarily update or revise any forward-looking statements included or incorporated by reference in this prospectus after the date hereof, either to conform them to actual results or to changes in our expectations.

Unless otherwise indicated in the prospectus supplement, we intend to use the net proceeds we receive from the offering of securities under this prospectus for general corporate purposes, including funding our investment activity, repayment of indebtedness and working capital. Further details relating to the use of net proceeds from the offering of securities under this prospectus will be set forth in the applicable prospectus supplement.

Pending such uses, the net proceeds may be invested in money market funds, bank accounts, overnight repurchase agreements with primary federal reserve bank dealers collateralized by direct U.S. government obligations and other instruments or investments reasonably determined by our Manager to be of high quality and that are consistent with our intention to qualify as a REIT and maintain our exclusion from regulation under the Investment Company Act of 1940, as amended, or the “Investment Company Act.”

We will not receive any of the proceeds from the sale of securities to which this prospectus relates that are offered by any selling securityholders.

RATIOS OF EARNINGS TO FIXED CHARGES AND EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS

The following table sets forth our historical ratios of earnings to fixed charges and earnings to combined fixed charges and preferred stock dividends for each of the periods indicated. For the purpose of calculating the ratio of earnings to fixed charges, “earnings” consist of income from continuing operations before income taxes and fixed charges, and “fixed charges” consist of interest on all indebtedness, amortized premiums, discounts and capitalized expenses related to indebtedness and preference security dividend requirements.

The following is a summary of the terms of our class A common stock and preferred stock, certain provisions of the Maryland General Corporation Law and provisions of our charter and bylaws containing the material terms of our class A common stock and preferred stock, which are qualified in their entirety by reference to the Maryland General Corporation Law, our charter and bylaws. Copies of our charter and bylaws are filed as exhibits to the registration statement of which this prospectus is part. See “Where You Can Find More Information.”

Under our charter, we may issue up to 200,000,000 shares of stock comprised of the following:

As of the date of this prospectus, 28,801,651 shares of our class A common stock were issued and outstanding and no shares of preferred stock were designated as a particular class or series or are outstanding. Under Maryland law, our stockholders generally are not liable for our debts or obligations. The class A common stock is listed on the NYSE under the symbol “BXMT”.

No warrants to purchase either class A common stock or preferred stock were issued or outstanding as of the date of this prospectus.

Our charter authorizes our board of directors, without stockholder approval, to:

Prior to the issuance of shares of each class or series, our board of directors is required by Maryland law and by our charter to set, subject to our charter restrictions on ownership and transfers of our stock, the terms, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications and terms or conditions of redemption for each class or series. Thus, our board could authorize the issuance of shares of common stock or preferred stock with terms and conditions which could have the effect of delaying, deferring or preventing a transaction or a change in control of Blackstone Mortgage Trust that might involve a premium price for holders of our class A common stock or otherwise be in their best interests.

Under Maryland law, a Maryland corporation generally cannot dissolve, amend its charter, merge, sell all or substantially all of its assets, engage in a statutory share exchange or engage in similar transactions outside the ordinary course of business unless approved by the affirmative vote of stockholders holding at least two-thirds of the shares entitled to vote on the matter. However, a Maryland corporation may provide in its charter for approval of these matters by a lesser percentage, but not less than a majority of all of the votes entitled to be cast on the matter. Our charter provides for approval of these matters by a majority of all of the votes entitled to be cast on the matter.

We are authorized to issue 100,000,000 shares of preferred stock. As of the date of this prospectus, no shares of preferred stock are outstanding. Our board of directors has the authority, without further action by the stockholders, to authorize us to issue shares of preferred stock in one or more class or series and to fix the number of shares, dividend rights, conversion rights, voting rights, redemption rights, liquidation preferences, sinking funds, and any other rights, preferences, privileges and restrictions applicable to each such series of preferred stock. The issuance of preferred stock could have the effect of making an attempt to gain control of us more difficult by means of a merger, tender offer, proxy contest or otherwise. The preferred stock, if issued, could have a preference on dividend payments that could affect our ability to make dividend distributions to the common stockholders. The preferred stock will, when issued, be duly authorized, fully paid and non-assessable.

A prospectus supplement relating to any series of preferred stock being offered will include specific terms relating to the offering. They will include, where applicable:

The terms, if any, on which the preferred stock may be convertible into or exchangeable for our class A common stock, preferred stock or other securities will be stated in the prospectus supplement relating to the preferred stock. The terms will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option, and may include provisions pursuant to which the number of shares of our class A common stock or other securities to be received by the holders of preferred stock would be subject to adjustment.

Our transfer agent and registrar is American Stock Transfer & Trust Company, LLC located in Brooklyn, New York.

Our charter further prohibits any person from beneficially or constructively owning shares of our stock that would result in our being “closely held” under Section 856(h) of the Internal Revenue Code or otherwise cause us to fail to qualify as a REIT and any person from transferring shares of our stock if the transfer would result in

our stock being owned by fewer than 100 persons. Any person who acquires or attempts or intends to acquire shares of our stock that may violate any of these restrictions, or who is the intended transferee of shares of our stock which are transferred to the trust, as described below, is required to give us immediate written notice, or in the case of a proposed or attempted transaction, give at least 15 days prior written notice, and provide us with such information as we may request in order to determine the effect of the transfer on our status as a REIT. The above restrictions will not apply if our board of directors determines that it is no longer in our best interests to continue to qualify as a REIT or that compliance with such restrictions is no longer required for us to qualify as a REIT.

Any attempted transfer of our stock which, if effective, would result in violation of the above limitations, except for a transfer which results in shares being owned by fewer than 100 persons, in which case such transfer will be void and of no force and effect and the intended transferee shall acquire no rights in such shares, will cause the number of shares causing the violation, rounded to the nearest whole share, to be automatically transferred to a trust for the exclusive benefit of one or more charitable beneficiaries designated by us and the proposed transferee will not acquire any rights in the shares. The automatic transfer will be deemed to be effective as of the close of business on the business day, as defined in our charter, prior to the date of the transfer. Shares of our stock held in the trust will be issued and outstanding shares. The proposed transferee will not benefit economically from ownership of any shares of stock held in the trust, will have no rights to dividends and no rights to vote or other rights attributable to the shares of stock held in the trust. The trustee of the trust will have all voting rights and rights to dividends or other distributions with respect to shares held in the trust. These rights will be exercised for the exclusive benefit of the charitable beneficiaries. Any dividend or other distribution paid prior to our discovery that shares of stock have been transferred to the trust will be paid by the recipient to the trustee upon demand. Any dividend or other distribution authorized but unpaid will be paid when due to the trustee. Any dividend or distribution paid to the trustee will be held in trust for the charitable beneficiaries. Subject to Maryland law, the trustee will have the authority to rescind as void any vote cast by the proposed transferee prior to our discovery that the shares have been transferred to the trust and to recast the vote in accordance with the desires of the trustee acting for the benefit of the charitable beneficiaries. However, if we have already taken irreversible corporate action, then the trustee will not have the authority to rescind and recast the vote.

Within 20 days of receiving notice from us that shares of our stock have been transferred to the trust, the trustee will sell the shares to a person designated by the trustee, whose ownership of the shares will not violate the above ownership limitations. Upon the sale, the interest of the charitable beneficiaries in the shares sold will terminate and the trustee will distribute the net proceeds of the sale to the proposed transferee and to the charitable beneficiaries as follows. The proposed transferee will receive the lesser of (i) the price paid by the proposed transferee for the shares or, if the proposed transferee did not give value for the shares in connection with the event causing the shares to be held in the trust, such as a gift, devise or other similar transaction, the market price, as defined in our charter, of the shares on the day of the event causing the shares to be held in the trust and (ii) the price per share received by the trustee from the sale or other disposition of the shares. Any net sale proceeds in excess of the amount payable per share to the proposed transferee will be paid immediately to the charitable beneficiaries. If, prior to our discovery that shares of our stock have been transferred to the trust, the shares are sold by the proposed transferee, then the shares shall be deemed to have been sold on behalf of the trust and, to the extent that the proposed transferee received an amount for the shares that exceeds the amount he was entitled to receive, the excess shall be paid to the trustee upon demand.

In addition, shares of our stock held in the trust will be deemed to have been offered for sale to us, or our designee, at a price per share equal to the lesser of (i) the price per share in the transaction that resulted in the transfer to the trust, or, in the case of a devise or gift, the market price at the time of the devise or gift and (ii) the market price on the date we, or our designee, accept the offer. We will have the right to accept the offer until the trustee has sold the shares. Upon a sale to us, the interest of the charitable beneficiaries in the shares sold will terminate and the trustee will distribute the net proceeds of the sale to the proposed transferee.

All certificates, if any, representing shares of our stock issued in the future will bear a legend referring to the restrictions described above.

Every owner of more than such percentage as may from time to time be established by our board of directors, or such lower percentage as required by the Internal Revenue Code or the regulations promulgated thereunder, of our stock, within 30 days after the end of each taxable year, is required to give us written notice, stating his or her name and address, the number of shares of each class and series of our stock which he or she beneficially owns and a description of the manner in which the shares are held. Each such owner shall provide us with such additional information as we may request in order to determine the effect, if any, of its beneficial ownership on our status as a REIT and to ensure compliance with the aggregate stock ownership limit. In addition, each stockholder shall, upon demand, be required to provide us with such information as we may request in good faith in order to determine our status as a REIT and to comply with the requirements of any taxing authority or governmental authority or to determine such compliance.

The statute permits various exemptions from its provisions, including business combinations that are exempted by the board of directors prior to the time that an interested stockholder becomes an interested stockholder. Our board of directors has exempted any business combination involving a limited liability company indirectly controlled by a trust for the benefit of Samuel Zell and his family. Our board of directors also approved in advance the transaction by which W.R. Berkley Corporation would have otherwise become an interested stockholder. In addition, our board of directors has exempted any business combination involving Huskies Acquisition LLC, or “Huskies Acquisition,” or its present affiliates or Blackstone and its present and future affiliates; provided, however, that Huskies Acquisition or any of its present affiliates and Blackstone and any of its present or future affiliates, may not enter into any “business combination” with Blackstone Mortgage Trust without the prior approval of at least a majority of the directors of our board of directors who are not affiliates or associates of Huskies Acquisition or Blackstone. As a result of the foregoing exemptions, these persons may enter into business combinations with us without compliance with the five-year prohibition, the super-majority vote requirements or the other provisions of the statute.

Control shares do not include shares the acquiror is entitled to vote as a result of having previously obtained stockholder approval or shares acquired directly from the corporation.

If voting rights are not approved at the meeting or if the acquiring person does not deliver an “acquiring person statement” as required by the statute, then the corporation may redeem for fair value any or all of the control shares, except those for which voting rights have previously been approved. The right of the corporation to redeem control shares is subject to certain conditions and limitations. Fair value is determined, without regard to the absence of voting rights for the control shares, as of the date of the last control share acquisition by the acquiror or of any meeting of stockholders at which the voting rights of the shares are considered and not approved. If voting rights for control shares are approved at a stockholders meeting and the acquiror becomes entitled to vote a majority of the shares entitled to vote, all other stockholders may exercise appraisal rights, unless the charter or bylaws provide otherwise. The fair value of the shares as determined for purposes of appraisal rights may not be less than the highest price per share paid by the acquiror in the control share acquisition.

Our charter authorizes us, to the maximum extent permitted by Maryland law, to obligate us to indemnify any present or former director or officer or any individual who, while a director or officer of the company and at the request of the company, serves or has served another corporation, real estate investment trust, partnership, limited liability company, joint venture, trust, employee benefit plan or other enterprise as a director, officer, partner or trustee, from and against any claim or liability to which that individual may become subject or which that individual may incur by reason of his or her service in such capacity and to pay or reimburse his or her reasonable expenses in advance of final disposition of a proceeding. Our bylaws obligate us, to the maximum extent permitted by Maryland law, to indemnify any present or former director or officer or any individual who, while a director or officer of the company and at the request of the company, serves or has served another corporation, real estate investment trust, partnership, joint venture, trust, employee benefit plan or other enterprise as a director, officer, partner or trustee and who is made or threatened to be made a party to the proceeding by reason of his or her service in that capacity from and against any claim or liability to which that individual may become subject or which that individual may incur by reason of his or her service in such capacity and to pay or reimburse his or her reasonable expenses in advance of final disposition of a proceeding. Our charter and bylaws also permit us to indemnify and advance expenses to any individual who served a predecessor of the company in any of the capacities described above and any employee or agent of the company or a predecessor of the company.

corporation’s receipt of (i) a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation and (ii) a written undertaking by him or her or on his or her behalf to repay the amount paid or reimbursed by the corporation if it is ultimately determined that the standard of conduct was not met.

The following description contains general terms and provisions of the depositary shares to which any prospectus supplement may relate. The particular terms of the depositary shares offered by any prospectus supplement and the extent, if any, to which such general provisions may not apply to the depositary shares so offered will be described in the prospectus supplement relating to such securities. For more information, please refer to the provisions of the deposit agreement we will enter into with a depositary to be selected, our charter and the form of articles supplementary for the applicable series of preferred stock.

We may, at our option, elect to offer depositary shares rather than full shares of preferred stock. In the event such option is exercised, each of the depositary shares will represent ownership of and entitlement to all rights and preferences of a fraction of a share of preferred stock of a specified series (including dividend, voting, redemption and liquidation rights). The applicable fraction will be specified in a prospectus supplement. The shares of preferred stock represented by the depositary shares will be deposited with a depositary named in the applicable prospectus supplement, under a deposit agreement, among Blackstone Mortgage Trust, the depositary and the holders of the certificates evidencing depositary shares, or “depositary receipts.” Depositary receipts will be delivered to those persons purchasing depositary shares in the offering. The depositary will be the transfer agent, registrar and dividend disbursing agent for the depositary shares. Holders of depositary receipts agree to be bound by the deposit agreement, which requires holders to take certain actions such as filing proof of residence and paying certain charges.

The depositary will distribute all cash dividends or other cash distributions received in respect of the series of preferred stock represented by the depositary shares to the record holders of depositary receipts in proportion to the number of depositary shares owned by such holders on the relevant record date, which will be the same date as the record date fixed by Blackstone Mortgage Trust for the applicable series of preferred stock. The depositary, however, will distribute only such amount as can be distributed without attributing to any depositary share a fraction of one cent, and any balance not so distributed will be added to and treated as part of the next sum received by the depositary for distribution to record holders of depositary receipts then outstanding.

In the event of a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary receipts entitled thereto, in proportion, as nearly as may be practicable, to the number of depositary shares owned by such holders on the relevant record date, unless the depositary determines (after consultation with Blackstone Mortgage Trust) that it is not feasible to make such distribution, in which case the depositary may (with the approval of Blackstone Mortgage Trust) adopt any other method for such distribution as it deems equitable and appropriate, including the sale of such property (at such place or places and upon such terms as it may deem equitable and appropriate) and distribution of the net proceeds from such sale to such holders.

In the event of the liquidation, dissolution or winding up of the affairs of Blackstone Mortgage Trust, whether voluntary or involuntary, the holders of each depositary share will be entitled to the fraction of the liquidation preference accorded each share of the applicable series of preferred stock as set forth in the prospectus supplement.

If the series of preferred stock represented by the applicable series of depositary shares is redeemable, such depositary shares will be redeemed from the proceeds received by the depositary resulting from the redemption, in whole or in part, of preferred stock held by the depositary. Whenever we redeem any preferred stock held by

the depositary, the depositary will redeem as of the same redemption date the number of depositary shares representing the preferred stock so redeemed. The depositary will mail the notice of redemption promptly upon receipt of such notice from us and not less than 30 nor more than 60 days prior to the date fixed for redemption of the preferred stock and the depositary shares to the record holders of the depositary receipts.

Promptly upon receipt of notice of any meeting at which the holders of the series of preferred stock represented by the applicable series of depositary shares are entitled to vote, the depositary will mail the information contained in such notice of meeting to the record holders of the depositary receipts as of the record date for such meeting. Each such record holder of depositary receipts will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the number of shares of preferred stock represented by such record holder’s depositary shares. The depositary will endeavor, insofar as practicable, to vote such preferred stock represented by such depositary shares in accordance with such instructions, and we will agree to take all action which may be deemed necessary by the depositary in order to enable the depositary to do so. The depositary will abstain from voting any of the preferred stock to the extent that it does not receive specific instructions from the holders of depositary receipts.

Upon surrender of depositary receipts at the principal office of the depositary, upon payment of any unpaid amount due the depositary, and subject to the terms of the deposit agreement, the owner of the depositary shares evidenced thereby is entitled to delivery of the number of whole shares of preferred stock and all money and other property, if any, represented by such depositary shares. Partial shares of preferred stock will not be issued. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the depositary will deliver to such holder at the same time a new depositary receipt evidencing such excess number of depositary shares. Holders of preferred stock thus withdrawn will not thereafter be entitled to deposit such shares under the deposit agreement or to receive depositary receipts evidencing depositary shares therefor.

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time and from time to time be amended by agreement between Blackstone Mortgage Trust and the depositary. However, any amendment which materially and adversely alters the rights of the holders (other than any change in fees) of depositary shares will not be effective unless such amendment has been approved by at least a majority of the depositary shares then outstanding. No such amendment may impair the right, subject to the terms of the deposit agreement, of any owner of any depositary shares to surrender the depositary receipt evidencing such depositary shares with instructions to the depositary to deliver to the holder of the preferred stock and all money and other property, if any, represented thereby, except in order to comply with mandatory provisions of applicable law.

The deposit agreement will be permitted to be terminated by Blackstone Mortgage Trust upon not less than 30 days prior written notice to the applicable depositary if (i) such termination is necessary to preserve our qualification as a REIT or (ii) a majority of each series of preferred stock affected by such termination consents to such termination, whereupon such depositary will be required to deliver or make available to each holder of depositary receipts, upon surrender of the depositary receipts held by such holder, such number of whole or fractional shares of preferred stock as are represented by the depositary shares evidenced by such depositary receipts together with any other property held by such depositary with respect to such depositary receipts. We will agree that if the deposit agreement is terminated to preserve our qualification as a REIT, then we will use our best efforts to list the preferred stock issued upon surrender of the related depositary shares on a national securities exchange. In addition, the deposit agreement will automatically terminate if (i) all outstanding

depositary shares thereunder shall have been redeemed, (ii) there shall have been a final distribution in respect of the related preferred stock in connection with any liquidation, dissolution or winding-up of Blackstone Mortgage Trust and such distribution shall have been distributed to the holders of depositary receipts evidencing the depositary shares representing such preferred stock or (iii) each share of the related preferred stock shall have been converted into stock of Blackstone Mortgage Trust not so represented by depositary shares.

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay charges of the depositary in connection with the initial deposit of the preferred stock and initial issuance of the depositary shares, and redemption of the preferred stock and all withdrawals of preferred stock by owners of depositary shares. Holders of depositary receipts will pay transfer, income and other taxes and governmental charges and certain other charges as are provided in the deposit agreement to be for their accounts. In certain circumstances, the depositary may refuse to transfer depositary shares, may withhold dividends and distributions and sell the depositary shares evidenced by such depositary receipt if such charges are not paid.

The depositary will forward to the holders of depositary receipts all reports and communications from us which are delivered to the depositary and which we are required to furnish to the holders of the preferred stock. In addition, the depositary will make available for inspection by holders of depositary receipts at the principal office of the depositary, and at such other places as it may from time to time deem advisable, any reports and communications received from us which are received by the depositary as the holder of preferred stock.

Neither the depositary nor Blackstone Mortgage Trust assumes any obligation or will be subject to any liability under the deposit agreement to holders of depositary receipts other than for its gross negligence or willful misconduct. Neither the depositary nor Blackstone Mortgage Trust will be liable if it is prevented or delayed by law or any circumstance beyond its control in performing its obligations under the deposit agreement. The obligations of Blackstone Mortgage Trust and the depositary under the deposit agreement will be limited to performance in good faith of their duties thereunder, and they will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. Blackstone Mortgage Trust and the depositary may rely on written advice of counsel or accountants, on information provided by holders of the depositary receipts or other persons believed in good faith to be competent to give such information and on documents believed to be genuine and to have been signed or presented by the proper party or parties.

In the event the depositary shall receive conflicting claims, requests or instructions from any holders of depositary receipts, on the one hand, and Blackstone Mortgage Trust, on the other hand, the depositary shall be entitled to act on such claims, requests or instructions received from Blackstone Mortgage Trust.

The depositary may resign at any time by delivering to us notice of its election to do so, and we may at any time remove the depositary, any such resignation or removal to take effect upon the appointment of a successor depositary and its acceptance of such appointment. Such successor depositary must be appointed within 60 days after delivery of the notice for resignation or removal and must be a bank or trust company having its principal office in the United States of America and having a combined capital and surplus of at least $150,000,000.

The following description contains general terms and provisions of the debt securities to which any prospectus supplement or related free writing prospectus may relate. The particular terms of the debt securities offered by any prospectus supplement or any related free writing prospectus and the extent, if any, to which such general provisions may not apply to the debt securities so offered will be described in the prospectus supplement or any free writing prospectus relating to such debt securities. For more information, please refer to the senior indenture we will enter into with the trustee named in the senior indenture, relating to the issuance of the senior debt securities, and the subordinated indenture we will enter into with the trustee named in the subordinated indenture, relating to issuance of the subordinated debt securities. Forms of these documents are filed as exhibits to the registration statement, which includes this prospectus.

As used in this prospectus, the term “indentures” refers to both the senior indenture and the subordinated indenture. The indentures will be qualified under and governed by the Trust Indenture Act of 1939, as amended, or “Trust Indenture Act.” As used in this prospectus, the term “trustee” refers to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.

The following are summaries of material provisions anticipated to be included in the senior indenture and the subordinated indenture. As summaries, they do not purport to be complete or restate the indentures in their entirety and are subject to, and qualified in their entirety by reference to, all provisions of the indentures and the debt securities. We urge you to read the indentures, including any related supplemental indentures, applicable to a particular series of debt securities because they, and not this description, define your rights as the holders of the debt securities. Except as we may otherwise indicate, the terms of the senior indenture and the subordinated indenture are substantially identical.

Each prospectus supplement will describe the terms relating to a series of debt securities, including without limitation:

The debt securities may be issued as original issue discount securities. An original issue discount security is a debt security, including any zero-coupon debt security, which:

United States federal income tax consequences applicable to debt securities sold at an original issue discount will be described in the applicable prospectus supplement. In addition, United States federal income tax or other consequences applicable to any debt securities which are denominated in a currency or currency unit other than United States dollars may be described in the applicable prospectus supplement.

Under the indentures, we will have the ability, in addition to the ability to issue debt securities with terms different from those of debt securities previously issued, without the consent of the holders, to reopen a previous issue of a series of debt securities and issue additional debt securities of that series, unless the reopening was restricted when the series was created, in an aggregate principal amount determined by us. The indentures do not limit the amount of debt securities that we may issue.

The terms, if any, on which a series of debt securities may be convertible into or exchangeable for our class A common stock, preferred stock or other securities will be described in the prospectus supplement or any free writing prospectus relating to that series of debt securities. The terms will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our class A or other class of common stock, preferred stock or other securities to be received by the holders of the series of debt securities would be subject to adjustment.

The subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in an applicable prospectus supplement. The subordinated indenture does not limit the amount of subordinated debt securities which we may issue, nor does it limit us from issuing any other secured or unsecured debt.

The indentures provide that we may consolidate with, or sell, lease or convey all or substantially all of our assets to, or merge with or into, any other person, provided that:

Unless we indicate otherwise in a prospectus supplement with respect to a particular series of debt securities, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change of control, any recapitalization transaction or in the event of a highly leveraged transaction (whether or not such transaction results in a change of control).

The following are events of default under the indentures with respect to any series of debt securities issued:

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the fourth bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice in writing to us, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately; provided, however, that the payment of principal of, premium, if any, and accrued interest, if any, on debt securities issued under the subordinated indenture shall remain subordinated to the extent provided in the subordinated indenture. If an event of default specified in the fourth bullet point above occurs, then all unpaid principal amounts, premium, if any, and accrued interest, if any, will immediately become due and payable, without any action by the trustee or any holder of debt securities. The trustee may withhold notice to the holders of debt securities of any default or event of default, except a default or event of default relating to the payment of principal or interest, if it determines that withholding such notice is in the holders’ interest.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to such series and its consequences, except a continuing default or events of default in the payment of principal, premium, if any, or interest on the debt securities of such series. Any such waiver shall cure such default or event of default.

Subject to the terms of the indentures, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee indemnity satisfactory to it. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with certain of the covenants in the indentures.

Each of the indentures will automatically cease to be of further effect as to any series of debt securities issued thereunder and the trustee, upon our demand and at our expense, will execute appropriate instruments acknowledging the satisfaction and discharge of the indenture with respect to such series upon compliance with the following conditions:

(2) our having paid or caused to be paid all sums payable by us under the indenture, as and when the same shall be due and payable; and

(3) our having delivered to the trustee an officers’ certificate and an opinion of counsel, each stating that all conditions relating to the satisfaction and discharge of the indenture have been complied with.

Unless the applicable prospectus supplement provides otherwise, the following discussion of legal defeasance and covenant defeasance will apply to any series of debt securities issued under either of the indentures.

We can legally release ourselves from any payment or other obligations on the debt securities of any series (called “legal defeasance”) if the following conditions are met:

If we ever accomplished legal defeasance, as described above, you would have to rely solely on the trust deposit for repayment of the debt securities. You could not look to us for repayment in the event of any shortfall.

However, even if we make the deposit in trust and deliver an opinion as discussed above, a number of our obligations relating to the debt securities will remain. These include, among others, our obligations to:

Purchasers of the debt securities should consult their own advisers with respect to the tax consequences to them of any deposit and discharge, including the applicability and effect of tax laws other than the U.S. federal income tax law.

Without any change in current U.S. federal income tax law, we can make the same type of deposit described above and be released from some of the covenants on the debt securities of any series. This is called “covenant defeasance.” In that event, you would lose the protection of those covenants but would gain the protection of having money and securities set aside in trust to repay the debt securities. In order to achieve covenant defeasance, the following conditions must be met:

If we accomplish covenant defeasance, you can still look to us for repayment of the debt securities if there were a shortfall in the trust deposit. In fact, if one of the Events of Default occurred (such as our bankruptcy) and the debt securities become immediately due and payable, there may be such a shortfall. Depending on the event causing the default, you may not be able to obtain payment of the shortfall.

We and the trustee may change an indenture without the consent of any holders with respect to the following matters:

In addition, under the indentures, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected, voting together as a single class. However, we can make the following changes only with the consent of each holder of any outstanding debt securities affected:

The debt securities of each series will be issuable only in fully registered form without coupons and, unless otherwise specified in the applicable prospectus supplement, in denominations of $2,000 and any integral multiple of $1,000 in excess thereof. The indentures will provide that debt securities of a series may be issuable in temporary or permanent global form and may be issued as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company or another depositary named by us and identified in a prospectus supplement or any free writing prospectus with respect to such series.

At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, debt securities of any series will be exchangeable for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, debt securities may be presented for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed, duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for such purpose. Unless otherwise provided in the debt securities to be transferred or exchanged, we will not require a service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges. The security registrar and any transfer agent initially designated by us for any debt securities will be named in the applicable prospectus supplement. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If the debt securities of any series are to be redeemed, we will not be required to:

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only such duties as are specifically described in the indentures and, upon an event of default under an indenture, must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered security and indemnity satisfactory to the trustee against the costs, expenses and liabilities that it might incur. The trustee is not required to spend or risk its own money or otherwise become financially liable while performing its duties unless it reasonably believes that it will be repaid or receive adequate indemnity.

Unless otherwise indicated in the applicable prospectus supplement, payment of the interest on any debt securities on any interest payment date will be made to the person in whose name such debt securities or one or more predecessor securities are registered at the close of business on the regular record date for such interest.

Principal of and any premium and interest on the debt securities of a particular series will be payable at the office of the paying agents designated by us, except that unless otherwise indicated in the applicable prospectus supplement, interest payments may be made by check mailed to the holder or by wire transfer. Unless otherwise indicated in such prospectus supplement, the corporate trust office of the trustee will be designated as our sole paying agent for payments with respect to debt securities of each series. Any other paying agents initially designated by us for the debt securities of a particular series will be named in the applicable prospectus supplement. We will be required to maintain a paying agent in each place of payment for the debt securities of a particular series.

All moneys paid by us to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities which remains unclaimed at the end of two years after the principal, premium or interest has become due and payable will be repaid to us, and the holder of the security may then look only to us for payment.

The indentures and each debt security will be deemed to be contracts made under the internal laws of the State of New York, and for all purposes will be construed in accordance with the laws of said state. The indentures are subject to the provisions of the Trust Indenture Act that are required to be part of the indentures and shall, to the extent applicable, be governed by such provisions.

The following description of the terms of the warrants sets forth certain general terms and provisions of the warrants to which any prospectus supplement may relate. We may issue warrants for the purchase of debt or equity securities described in this prospectus. Warrants may be issued independently or together with any offered securities and may be attached to or separate from such securities. Each series of warrants will be issued under one or more warrant agreements we will enter into with a warrant agent specified in the agreement. The warrant agent will act solely as our agent in connection with the warrants of that series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants. The following summary of certain provisions of the warrants does not purport to be complete and is subject to, and qualified in its entirety by reference to, the provisions of the warrant agreement that will be filed with the SEC in connection with an offering of our warrants.

A prospectus supplement relating to any series of warrants being offered will include specific terms relating to the offering. They will include, where applicable:

The following is a general description of the terms of the subscription rights we may issue from time to time. Particular terms of any subscription rights we offer will be described in the prospectus supplement relating to such subscription rights.

We may issue subscription rights to purchase our equity or debt securities. These subscription rights may be issued independently or together with any other security offered hereby and may or may not be transferable by the stockholder receiving the subscription rights in such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

The applicable prospectus supplement will describe the specific terms of any offering of subscription rights for which this prospectus is being delivered, including the following:

The description in the applicable prospectus supplement of any subscription rights we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable subscription rights certificate or subscription rights agreement, which will be filed with the SEC if we offer subscription rights.

We may issue purchase contracts, including contracts obligating holders to purchase from or sell to us, and for us to sell to or purchase from the holders, a specified principal amount of debt securities or a specified number of shares of common stock, shares of preferred stock or depositary shares at a future date or dates. The consideration for the debt securities, common stock, preferred stock or depositary shares and the principal amount of debt securities or number of shares of each may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula set forth in the purchase contracts. The purchase contracts may be issued separately or as part of units, often known as purchase units, consisting of a purchase contract and other securities or obligations issued by us or third parties, including U.S. Treasury securities, which may secure the holders’ obligations to purchase the debt securities, common stock, preferred stock or depositary shares under the purchase contracts. The purchase contracts may require us to make periodic payments to the holders of the purchase contracts or units or vice versa, and these payments may be unsecured or prefunded on some basis. The purchase contracts may require holders to secure their obligations under those contracts in a specified manner.

The applicable prospectus supplement will describe the terms of the purchase contracts and purchase units, including, if applicable, collateral or depositary arrangements.

As specified in the applicable prospectus supplement, we may issue units consisting of one or more shares of common stock, shares of preferred stock, depositary shares, debt securities, warrants, subscription rights, purchase contracts or any combination of such securities.

The applicable prospectus supplement will specify the following terms of any units in respect of which this prospectus is being delivered:

We may issue series of any securities as global securities and deposit them with a depositary with respect to that series. Unless otherwise indicated in the applicable prospectus supplement, the following is a summary of the depositary arrangements applicable to securities issued in permanent global form and for which The Depository Trust Company, or “DTC,” will act as depositary.

Each global security will be deposited with, or on behalf of, DTC, as depositary, or its nominee and registered in the name of a nominee of DTC. Except under the limited circumstances described below, global securities will not be exchangeable for certificated securities.

Only institutions that have accounts with DTC or its nominee, or “DTC participants,” or persons that may hold interests through DTC participants may own beneficial interests in a global security. DTC will maintain records evidencing ownership of beneficial interests by DTC participants in the global securities and transfers of those ownership interests. DTC participants will maintain records evidencing ownership of beneficial interests in the global securities by persons that hold through those DTC participants and transfers of those ownership interests within those DTC participants. DTC has no knowledge of the actual beneficial owners of the securities. You will not receive written confirmation from DTC of your purchase, but we do expect that you will receive written confirmations providing details of the transaction, as well as periodic statements of your holdings, from the DTC participant through which you entered the transaction. The laws of some jurisdictions require that certain purchasers of securities take physical delivery of those securities in certificated form. Those laws may impair your ability to transfer beneficial interests in a global security.

We understand that upon the issuance of a global security and the deposit of that global security with DTC, DTC will immediately credit, on its book-entry registration and transfer system, the respective principal amounts or number of shares represented by that global security to the accounts of DTC participants.

We will make payments on securities represented by a global security to DTC or its nominee, as the case may be, as the registered owner and holder of the global security representing those securities. We understand that upon receipt of any payment on a global security, DTC will immediately credit accounts of DTC participants with payments in amounts proportionate to their respective beneficial interests in that security, as shown in the records of DTC. Standing instructions and customary practices will govern payments by DTC participants to owners of beneficial interests in a global security held through those DTC participants, as is now the case with securities held for the accounts of customers in bearer form or registered in “street name.” Those payments will be the sole responsibility of those DTC participants, subject to any statutory or regulatory requirements in effect from time to time.

A global security is exchangeable for certificated securities registered in the name of a person other than DTC or its nominee only if:

Any global security that is exchangeable as described in the preceding sentence will be exchangeable in whole for certificated securities in registered form, and, in the case of global debt securities, of like tenor and of an equal aggregate principal amount as the global security, in denominations of $2,000 and integral multiples of $1,000 (or in denominations and integral multiples as otherwise specified in the applicable prospectus supplement). The registrar for the securities will register the certificated securities in the name or names

instructed by DTC. We expect that those instructions may be based upon directions received by DTC from DTC participants with respect to ownership of beneficial interests in the global security. In the case of global debt securities, unless otherwise specified in the prospectus supplement, we will make payment of any principal and interest on the certificated securities and will register transfers and exchanges of those certificated securities at the corporate trust office of The Bank of New York Mellon Trust Company, N.A. However, we may elect to pay interest by check mailed to the address of the person entitled to that interest payment as of the record date, as shown on the register for the securities.

Except as provided above, as an owner of a beneficial interest in a global security, you will not be entitled to receive physical delivery of securities in certificated form and will not be considered a holder of securities for any purpose under either of the indentures. No global security will be exchangeable except for another global security of like denomination and tenor to be registered in the name of DTC or its nominee. Accordingly, you must rely on the procedures of DTC and the DTC participant through which you own your interest to exercise any rights of a holder under the global security or the applicable indenture.

We understand that, under existing industry practices, in the event that we request any action of holders, or an owner of a beneficial interest in a global security desires to take any action that a holder is entitled to take under the securities or the indentures, DTC would authorize the DTC participants holding the relevant beneficial interests to take that action, and those DTC participants would authorize beneficial owners owning through those DTC participants to take that action or would otherwise act upon the instructions of beneficial owners owning through them.

We understand that DTC is a limited purpose trust company organized under the New York Banking Law, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code and a “clearing agency” registered under the Exchange Act.

If specified in the applicable prospectus supplement, investors may elect to hold interests in the offered securities outside the United States through Clearstream Banking, société anonyme, or “Clearstream,” or Euroclear Bank S.A./N.V., as operator of the Euroclear System, or “Euroclear,” if they are participants in those systems, or indirectly through organizations that are participants in those systems. Clearstream and Euroclear will hold interests on behalf of their participants through customers’ securities accounts in Clearstream’s and Euroclear’s names on the books of their respective depositaries. Those depositaries in turn hold those interests in customers’ securities accounts in the depositaries’ names on the books of DTC. Unless otherwise specified in the prospectus supplement, Citibank, N.A. will act as the depositary for Clearstream and JPMorgan Chase Bank, N.A. will act as the depositary for Euroclear.

We understand that Clearstream is incorporated under the laws of Luxembourg as a professional depositary. Clearstream holds securities for its participants and facilitates the clearance and settlement of securities transactions between its participants through electronic book-entry transfers between their accounts and interfaces with domestic securities markets in several countries through established depositary and custodial relationships. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Commission for the Supervision of the Financial Sector, also known as the Commission de Surveillance du Secteur Financier. Clearstream participants are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and other organizations. Clearstream’s participants in the United States are limited to securities brokers and dealers and banks. Indirect access to Clearstream is also available to other institutions such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with Clearstream participants.

Distributions with respect to interests in global securities held through Clearstream will be credited to cash accounts of its customers in accordance with its rules and procedures, to the extent received by the U.S. depositary for Clearstream.

We understand that Euroclear was created in 1968 to hold securities for its participants and to clear and settle transactions between Euroclear participants through simultaneous electronic book-entry delivery against payment and interfaces with domestic markets in several countries. Euroclear is operated by Euroclear Bank S.A./N.V. (the “Euroclear operator”) under contract with Euroclear plc, a U.K. corporation. Euroclear participants include banks, including central banks, securities brokers and dealers and other professional financial intermediaries. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear participant, either directly or indirectly.

Distributions with respect to interests in global securities held beneficially through Euroclear will be credited to the cash accounts of Euroclear participants in accordance with Euroclear’s terms and conditions and operating procedures and applicable Belgian law, to the extent received by the U.S. depositary for Euroclear.

Unless otherwise specified in a prospectus supplement with respect to a particular series of global securities, initial settlement for global securities will be made in immediately available funds. DTC participants will conduct secondary market trading with other DTC participants in the ordinary way in accordance with DTC rules. Thereafter, secondary market trades will settle in immediately available funds using DTC’s same day funds settlement system.

If the prospectus supplement specifies that interests in the global securities may be held through Clearstream or Euroclear, Clearstream customers and/or Euroclear participants will conduct secondary market trading with other Clearstream customers and/or Euroclear participants in the ordinary way in accordance with the applicable rules and operating procedures of Clearstream and Euroclear. Thereafter, secondary market trades will settle in immediately available funds.

Cross-market transfers between persons holding directly or indirectly through DTC on the one hand, and directly or indirectly through Clearstream customers or Euroclear participants, on the other, will be effected in DTC in accordance with DTC’s rules on behalf of the relevant European international clearing system by the U.S. depositary for that system; however, those cross-market transactions will require delivery by the counterparty in the relevant European international clearing system of instructions to that system in accordance with its rules and procedures and within its established deadlines (European time). The relevant European international clearing system will, if the transaction meets its settlement requirements, deliver instructions to the U.S. depositary for that system to take action to effect final settlement on its behalf by delivering or receiving interests in global securities in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Clearstream customers and Euroclear participants may not deliver instructions directly to DTC.

Because of time-zone differences, credits of interests in global securities received in Clearstream or Euroclear as a result of a transaction with a DTC participant will be made during subsequent securities settlement processing and will be credited the business day following the DTC settlement date. Those credits or any transactions in global securities settled during that processing will be reported to the relevant Euroclear participants or Clearstream customers on that business day. Cash received in Clearstream or Euroclear as a result of sales of interests in global securities by or through a Clearstream customer or a Euroclear participant to a DTC participant will be received with value on the DTC settlement date but will be available in the relevant Clearstream or Euroclear cash account only as of the business day following settlement in DTC.

Although we understand that DTC, Clearstream and Euroclear have agreed to the procedures described above in order to facilitate transfers of interests in global securities among DTC participants, Clearstream and Euroclear, they are under no obligation to perform those procedures and those procedures may be discontinued at any time.

Neither we nor the selling securityholders, the trustees or any of our respective agents will have any responsibility or liability for any aspect of the records of DTC, Clearstream or Euroclear, any nominee or any DTC, Clearstream or Euroclear participant relating to, or payments made on account of, beneficial interests in a global security or for maintaining, supervising or reviewing any of the records of DTC, Clearstream or Euroclear, any nominee or any DTC, Clearstream or Euroclear participant relating to those beneficial interests.

The following summary describes the material United States federal income tax considerations relating to the ownership of class A common stock as of the date hereof by United States and non-United States holders, each as defined below. We will summarize any special United States federal income tax considerations relevant to a particular issue of securities other than our class A common stock in the applicable prospectus supplement. Except where noted, this summary deals only with class A common stock held as a capital asset and does not deal with special situations, such as those of dealers in securities or currencies, financial institutions, regulated investment companies, tax-exempt entities (except as described in “—Taxation of Tax-Exempt Holders of Our Class A Common Stock” below), insurance companies, persons holding class A common stock as a part of a hedging, integrated, conversion or constructive sale transaction or a straddle, traders in securities that elect to use a mark-to-market method of accounting for their securities holdings, persons liable for alternative minimum tax, investors in pass-through entities or United States holders of class A common stock whose “functional currency” is not the United States dollar. Furthermore, the discussion below is based upon the provisions of the Internal Revenue Code and regulations, rulings and judicial decisions thereunder as of the date hereof, and such authorities may be repealed, revoked or modified, possibly with retroactive effect, so as to result in United States federal income tax consequences different from those discussed below.

In connection with the filing of this prospectus, Simpson Thacher & Bartlett LLP is expected to render an opinion that, commencing with the taxable year ended December 31, 2008, Blackstone Mortgage Trust has been organized in conformity with the requirements for qualification and taxation as a REIT under the Internal Revenue Code, and its actual and proposed method of operation as described in this prospectus has enabled it, and will continue to enable it, to meet the requirements for qualification and taxation as a REIT under the Internal Revenue Code. Investors should be aware that the opinion of Simpson Thacher & Bartlett LLP will be based upon customary assumptions, will be conditioned upon certain representations made by us as to factual matters, including representations regarding the nature of our assets and the conduct of our business, and will not be binding upon the IRS or any court. We have not received, and do not intend to seek, any rulings from the IRS regarding our status as a REIT or our satisfaction of the REIT requirements. The IRS may challenge our status a REIT, and a court could sustain any such challenge. In addition, the opinion of Simpson Thacher & Bartlett LLP will be based on existing federal income tax law governing qualification as a REIT, which is subject to change either prospectively or retroactively. Moreover, our qualification and taxation as a REIT depend upon our ability to meet on a continuing basis, through actual annual operating results, certain qualification tests set forth in the federal tax laws. Those qualification tests involve the percentage of income that we earn from specified sources, the percentage of our assets that falls within specified categories, the diversity of the ownership of our shares, and the percentage of our earnings that we distribute. Simpson Thacher & Bartlett LLP will not review our compliance with those tests on a continuing basis. Accordingly, no assurance can be given that our actual results of operations for any particular taxable year will satisfy such requirements. For a discussion of the tax consequences of our failure to qualify as a REIT, see “—Failure to Qualify.”

The sections of the Internal Revenue Code and the corresponding regulations that govern the United States federal income tax treatment of a REIT and its stockholders are highly technical and complex. The following discussion is qualified in its entirety by the applicable Internal Revenue Code provisions, rules and regulations promulgated thereunder, and administrative interpretations thereof.

We are generally not subject to United States corporate income tax on income that we distribute currently to stockholders, but we will be subject to United States federal tax as follows:

Requirements for Qualification as a REIT. The Internal Revenue Code defines a REIT as a corporation, trust or association:

Conditions (1) through (4), inclusive, must be met during the entire taxable year. Condition (5) must be met during at least 335 days of a taxable year of 12 months, or during a proportionate part of a taxable year of less than 12 months other than the first taxable year for which an election to become a REIT is made. Condition (6) must be met during the last half of each taxable year but neither conditions (5) nor (6) apply to the first taxable year for which an election to become a REIT is made. We believe that we have maintained and will maintain sufficient diversity of ownership to allow us to continue to satisfy conditions (5) and (6) above. In addition, our charter contains restrictions regarding the ownership and transfer of our stock that are intended to assist us in continuing to satisfy the share ownership requirements described in (5) and (6) above. The provisions of our charter restricting the ownership and transfer of our stock are described in “Description of Capital Stock—Certain Provisions of Our Charter and Bylaws and of Maryland Law—REIT Qualification Restrictions on Ownership and Transfer.” These restrictions, however, may not ensure that we will be able to satisfy these share ownership requirements. If we fail to satisfy these share ownership requirements, we will fail to qualify as a REIT.

To monitor compliance with the share ownership requirements, we generally are required to maintain records regarding the actual ownership of our shares. To do so, we must demand written statements each year from the record holders of significant percentages of our stock pursuant to which the record holders must disclose the actual owners of the shares (i.e., the persons required to include our dividends in their gross income). We must maintain a list of those persons failing or refusing to comply with this demand as part of our records. We could be subject to monetary penalties if we fail to comply with these record-keeping requirements. If you fail or refuse to comply with the demands, you will be required by United States Treasury regulations to submit a statement with your tax return disclosing your actual ownership of our shares and other information. In addition, we must satisfy all relevant filing and other administrative requirements established by the IRS to elect and maintain REIT status, use a calendar year for federal income tax purposes, and comply with the record keeping requirements of the Internal Revenue Code and regulations promulgated thereunder.

certain excluded securities as described in the Internal Revenue Code. In addition, the assets and gross income of the partnership generally are deemed to retain the same character in the hands of the REIT. Thus, our proportionate share of the assets and items of income of partnerships in which we own an equity interest is treated as assets and items of income of our company for purposes of applying the REIT requirements described below. Consequently, to the extent that we directly or indirectly hold a preferred or other equity interest in a partnership, the partnership’s assets and operations may affect our ability to qualify as a REIT, even though we may have no control or only limited influence over the partnership.

Several provisions of the Internal Revenue Code regarding the arrangements between a REIT and its taxable REIT subsidiaries ensure that a taxable REIT subsidiary will be subject to an appropriate level of United States federal income taxation. For example, a taxable REIT subsidiary is limited in its ability to deduct interest payments made to affiliated REITs. In addition, we would be obligated to pay a 100% penalty tax on some payments that we receive from, or on certain expenses deducted by, a taxable REIT subsidiary if the IRS were to assert successfully that the economic arrangements between us and a taxable REIT subsidiary are not comparable to similar arrangements among unrelated parties.

An entity or portion of an entity will be treated as a REMIC for purposes of the Internal Revenue Code if:

to unrelated business income tax (such as a government entity), we would be taxable on this income at the highest applicable corporate tax rate (currently 35%). The manner in which excess inclusion income would be allocated among shares of different classes of our stock or how such income is to be reported to stockholders is not clear under current law. Tax-exempt investors, non-United States investors and taxpayers with net operating losses should carefully consider the tax consequences described above and are urged to consult their tax advisors in connection with their decision to invest in our class A common stock.

We expect that the CMBS and residential mortgage-backed securities, or “RMBS,” in which we invest generally will be treated either as interests in a grantor trust or as interests in a REMIC for United States federal income tax purposes and that all interest income from such CMBS and RMBS will be qualifying income for the 95% gross income test. In the case of CMBS and RMBS treated as interests in grantor trusts, we would be treated as owning an undivided beneficial ownership interest in the mortgage loans held by the grantor trust. The interest on such mortgage loans would be qualifying income for purposes of the 75% gross income test to the extent that the obligation is secured by real property, as discussed above. In the case of CMBS and RMBS treated as interests in a REMIC, income derived from REMIC interests will generally be treated as qualifying income for purposes of the 75% and 95% gross income tests. If less than 95% of the assets of the REMIC are real estate assets, however, then only a proportionate part of our interest in the REMIC and income derived from the interest will qualify for purposes of the 75% gross income test. In addition, some REMIC securitizations include imbedded interest swap or cap contracts or other derivative instruments that potentially could produce non-qualifying income for the holder of the related REMIC securities.

The interest, original issue discount, and market discount income that we will receive from our mortgage-related assets generally will be qualifying income for purposes of both gross income tests.

Rents from Real Property. To the extent that we own or acquire real property or an interest therein, rents we receive will qualify as “rents from real property” in satisfying the gross income requirements for a REIT described above only if several conditions are met. These conditions relate to the identity of the tenant, the computation of the rent payable, and the nature of the property leased. First, the amount of rent must not be based in whole or in part on the income or profits of any person. However, an amount received or accrued generally will not be excluded from rents from real property solely by reason of being based on a fixed percentage or percentages of receipts or sales. Second, rents we receive from a “related party tenant” will not qualify as rents from real property in satisfying the gross income tests unless the tenant is a taxable REIT subsidiary, at least 90% of the property is leased to unrelated tenants, the rent paid by the taxable REIT subsidiary is substantially comparable to the rent paid by the unrelated tenants for comparable space and the rent is not attributable to an increase in rent due to a modification of a lease with a “controlled taxable REIT subsidiary” (i.e., a taxable REIT subsidiary in which we own directly or indirectly more than 50% of the voting power or value of the stock). A tenant is a related party tenant if the REIT, or an actual or constructive owner of 10% or more of the REIT, actually or constructively owns 10% or more of the tenant. Third, if rent attributable to personal property leased in connection with a lease of real property is greater than 15% of the total rent received under the lease, then the portion of rent attributable to the personal property will not qualify as rents from real property. Finally, for rents to qualify as “rents from real property” for purposes of the gross income tests, we are only allowed to provide services that are both usually or “customarily rendered” in connection with the rental of real property and not otherwise considered “rendered to the occupant.” We may, however, render services to our tenants through an “independent contractor” who is adequately compensated and from whom we do not derive revenue. We may also own a taxable REIT subsidiary which provides non-customary services to tenants without tainting our rental income from the related properties.

more than 1% of all amounts received or accrued, directly or indirectly by the REIT with respect to the property during the same taxable year, then only the amounts with respect to such non-customary services are not treated as rent for purposes of the REIT gross income tests.

Foreclosure Property. Foreclosure property is any real property, including interests in real property, and any personal property incident to such real property:

As a result of each of these potential timing differences between income recognition or expense deduction and cash receipts or disbursements, there is a significant risk that we may have substantial taxable income in excess of cash available for distribution. In that event, we may need to borrow funds or take other action to satisfy the REIT distribution requirements for the taxable year in which this “phantom income” is recognized. See “—Annual Distribution Requirements Applicable to REITs.”

At the close of each quarter of our taxable year, we must satisfy the following tests relating to the nature of our assets.

the law on the matter is not entirely clear, it appears that the non-qualifying portion of that mortgage loan will be equal to the portion of the loan amount that exceeds the value of the associated real property that is security for that loan. Debt securities issued by other REITs or C corporations that are not secured by mortgages on real property will not be qualifying assets for purposes of the 75% asset test.

After initially meeting the asset tests after the close of any quarter, we will not lose our status as a REIT if we fail to satisfy the asset tests at the end of a later quarter solely by reason of changes in the relative values of our assets. However, an acquisition of property by a REIT requires the REIT to revalue all of its assets. If the failure to satisfy the asset tests results from an increase in the value of our assets after the acquisition of securities or other property during a quarter, the failure can be cured by eliminating the discrepancy within 30 days after the close of that quarter. We intend to maintain adequate records of the value of our assets to ensure compliance with the asset tests and to take any available action within 30 days after the close of any quarter as may be required to cure any noncompliance with the asset tests. We cannot ensure that these steps always will be successful. If we fail to cure the noncompliance with the asset tests within this 30-day period, we could fail to qualify as a REIT.

To qualify as a REIT, we generally must distribute dividends (other than capital gain dividends) to our stockholders in an amount at least equal to:

distribution requirements to arrange for short-term, or possibly long-term, borrowings, or to pay the dividends in the form of taxable in-kind distributions of property (including, for example, our own debt securities).

If a partnership (or an entity treated as a partnership for U.S. federal income tax purposes) holds our class A common stock, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership holding class A common stock, you should consult your advisors. A “non-United States holder” is a beneficial owner of our class A common stock that is neither a United States holder nor a partnership (or an entity treated as a partnership for U.S. federal income tax purposes).

Distributions Generally. As long as we qualify as a REIT, distributions made to taxable United States holders of our class A common stock out of current or accumulated earnings and profits that are not designated as capital gain dividends or “qualified dividend income” will be taken into account by them as ordinary income taxable at ordinary income tax rates and will not qualify for the reduced capital gains rates that currently generally apply to distributions by non-REIT C corporations to certain non-corporate United States holders. In determining the extent to which a distribution constitutes a dividend for tax purposes, our earnings and profits will be allocated first to distributions with respect to our preferred stock, if any, and then to our class A common stock. Corporate stockholders will not be eligible for the dividends received deduction with respect to these distributions.

We will be treated as having sufficient earnings and profits to treat as a dividend any distribution we pay up to the amount required to be distributed in order to avoid imposition of the 4% excise tax discussed above. Moreover, any “deficiency dividend” will be treated as an ordinary or capital gain dividend, as the case may be, regardless of our earnings and profits. As a result, United States holders may be required to treat certain distributions that would otherwise result in a tax-free return of capital as taxable dividends.

We must classify portions of our designated capital gain dividend into the following categories:

Distributions. Distributions by us to a non-United States holder of our class A common stock that are neither attributable to gain from sales or exchanges by us of “United States real property interests” nor designated by us as capital gains dividends will be treated as dividends of ordinary income to the extent that they are made out of our current or accumulated earnings and profits. These distributions ordinarily will be subject to United States federal income tax on a gross basis at a rate of 30%, or a lower rate as permitted under an applicable income tax treaty, unless the dividends are treated as effectively connected with the conduct by the non-United States holder of a United States trade or business. Under some treaties, however, lower rates generally applicable to dividends do not apply to dividends from REITs. Further, reduced treaty rates are not available to the extent the income allocated to the non-United States stockholder is excess inclusion income. Excess inclusion income will generally be allocated to our stockholders to the extent we have “excess inclusion income” that exceeds our undistributed REIT taxable income in a particular year. See “—Our Taxation as a REIT—Taxable Mortgage Pools and REMICs.” Dividends that are effectively connected with a trade or business will be subject to tax on a net basis, that is, after allowance for deductions, at graduated rates, in the same manner as United States holders are taxed with respect to these dividends, and are generally not subject to withholding. Applicable certification and disclosure requirements must be satisfied to be exempt from withholding under the effectively connected income exception. Any dividends received by a corporate non-United States holder that is engaged in a United States trade or business also may be subject to an additional branch profits tax at a 30% rate, or lower applicable treaty rate. We expect to withhold United States income tax at the rate of 30% on any dividend distributions, not designated as (or deemed to be) capital gain dividends, made to a non-United States holder unless:

period ending on the date of such dividend. Instead, any capital gain dividend will be treated as a distribution subject to the rules discussed above under “—Taxation of Non-United States Stockholders of Our Class A Common Stock—Distributions.” Also, the branch profits tax will not apply to such a distribution.

Sales of Our Class A Common Stock. Gain recognized by a non-United States holder upon the sale or exchange of our stock generally would not be subject to United States taxation unless:

A common stock and subsequently acquired additional shares of class A common stock at a later date, then all such shares of class A common stock would be aggregated and valued as of the date of the subsequent acquisition.

If gain on the sale or exchange of our class A common stock were subject to taxation under FIRPTA, the non-United States holder would be subject to regular United States income tax with respect to any gain in the same manner as a taxable United States holder, subject to any applicable alternative minimum tax and special alternative minimum tax in the case of nonresident alien individuals. In such case, under FIRPTA the purchaser of class A common stock may be required to withhold 10% of the purchase price and remit this amount to the IRS. In addition, distributions that are treated as gain from the disposition of class A common stock and are subject to tax under FIRPTA also may be subject to a 30% branch profits tax when made to a corporate non-United States holder that is not entitled to a treaty exemption.

Provided that a tax-exempt holder has not held its class A common stock as “debt-financed property” within the meaning of the Internal Revenue Code and our shares of stock are not being used in an unrelated trade or business, the dividend and interest income from us generally will not be unrelated business taxable income, referred to as UBTI, to a tax-exempt holder. Similarly, income from the sale of our class A common stock will not constitute UBTI unless the tax-exempt holder has held its class A common stock as debt-financed property within the meaning of the Internal Revenue Code or has used the class A common stock in a trade or business. To the extent, however, that we, or a part of us, or a disregarded subsidiary of ours, is a taxable mortgage pool, a portion of the dividends paid to a tax-exempt stockholder that is allocable to excess inclusion income may be subject to tax as UBTI. Excess inclusion income will generally be allocated to our stockholders to the extent we have excess inclusion income that exceeds our undistributed REIT taxable income in a particular year. See “—Our Taxation as a REIT—Taxable Mortgage Pools and REMICs.”

any year, in which case none of the dividends would be treated as UBTI. The provisions requiring pension trusts to treat a portion of REIT distributions as UBTI will not apply if the REIT is not a “pension-held REIT” (for example, if the REIT is able to satisfy the “not closely held requirement” without relying on the “look through” exception with respect to pension trusts).

United States Holders of Class A Common Stock. In general, information-reporting requirements will apply to payments of dividends and interest on and payments of the proceeds of the sale of our class A common stock held by United States holders, unless an exception applies. The payor is required to withhold tax on such payments if (i) the payee fails to furnish a taxpayer identification number, or TIN, to the payor or to establish an exemption from backup withholding, or (ii) the IRS notifies the payor that the TIN furnished by the payee is incorrect. In addition, a payor of the dividends or interest on our class A common stock is required to withhold tax if (i) there has been a notified payee under-reporting with respect to interest, dividends or original issue discount described in Section 3406(c) of the Internal Revenue Code, or (ii) there has been a failure of the payee to certify under the penalty of perjury that the payee is not subject to backup withholding under the Internal Revenue Code. A United States holder that does not provide us with a correct taxpayer identification number may also be subject to penalties imposed by the IRS. In addition, we may be required to withhold a portion of capital gain distributions to any United States holders who fail to certify their United States status to us. Some United States holders of our class A common stock, including corporations, may be exempt from backup withholding. Any amounts withheld under the backup withholding rules from a payment to a stockholder will be allowed as a credit against the stockholder’s United States federal income tax and may entitle the stockholder to a refund, provided that the required information is furnished to the IRS. The payor will be required to furnish annually to the IRS and to holders of our class A common stock information relating to the amount of dividends and interest paid on our class A common stock, and that information reporting may also apply to payments of proceeds from the sale of our class A common stock. Some holders, including corporations, financial institutions and certain tax-exempt organizations, are generally not subject to information reporting.

Non-United States Holders of Our Class A Common Stock. Generally, information reporting will apply to payments of interest and dividends on our class A common stock, and backup withholding described above for a United States holder will apply, unless the payee certifies that it is not a United States person or otherwise establishes an exemption.

The payment of the proceeds from the disposition of our class A common stock to or through the United States office of a United States or foreign broker will be subject to information reporting and backup withholding as described above for United States holders unless the non-United States holder satisfies the requirements necessary to be an exempt non-United States holder or otherwise qualifies for an exemption. The proceeds of a disposition by a non-United States holder of our class A common stock to or through a foreign office of a broker generally will not be subject to information reporting or backup withholding. However, if the broker is a United States person, a controlled foreign corporation for United States tax purposes, a foreign person 50% or more of whose gross income from all sources for specified periods is from activities that are effectively connected with a United States trade or business, a foreign partnership if partners who hold more than 50% of the interest in the partnership are United States persons, or a foreign partnership that is engaged in the conduct of a trade or business in the United States, then information reporting generally will apply as though the payment was made through a United States office of a United States or foreign broker.

Applicable Treasury regulations provide presumptions regarding the status of a holder of our class A common stock when payments to such holder cannot be reliably associated with appropriate documentation provided to the payer. Because the application of these Treasury regulations varies depending on the stockholder’s particular circumstances, you are advised to consult your tax advisor regarding the information reporting requirements applicable to you.

Under certain provisions of the Hiring Incentives to Restore Employment Act, which was enacted in March 2010, and administrative guidance thereto, the relevant withholding agent may be required to withhold 30% of any dividends paid after June 30, 2014 and the proceeds of a sale or other disposition of our class A common stock occurring after December 31, 2016 paid to (i) a foreign financial institution unless such foreign financial institution agrees to verify, report and disclose its U.S. accountholders and meets certain other specified requirements, or otherwise complies with the Foreign Account Tax Compliance Act of 2009 or (ii) a non-financial foreign entity that is the beneficial owner of the payment unless such entity certifies that it does not have any substantial United States owners or provides the name, address and taxpayer identification number of each substantial United States owner and such entity meets certain other specified requirements. Non-United States holders should consult their tax advisors to determine the applicability of this legislation in light of their individual circumstances.

We and/or the selling securityholders may sell the securities being offered by this prospectus in one or more of the following ways from time to time:

A distribution of the securities offered by this prospectus may also be effected through the issuance of derivative securities, including without limitation, warrants, subscriptions, exchangeable securities, forward delivery contracts and the writing of options. In addition, the manner in which we and/or the selling securityholders may sell some or all of the securities covered by this prospectus includes, without limitation, through:

We may also enter into derivative, hedging, forward sale, option or other types of transactions. For example, we may:

In addition, we may enter into derivative, hedging, forward sale, option or other types of transactions with third parties, or sell securities not covered by this prospectus to third parties, through a stock exchange, including block trades or ordinary broker’s transactions, or through broker-dealers acting either as principal or agent, or through an underwritten public offering, through privately negotiated transactions or through a combination of any such methods of sale. In connection with such a transaction, the third parties may sell securities covered by and pursuant to this prospectus and an applicable prospectus supplement or pricing supplement, as the case may be. If so, the third party may use securities borrowed from us or others to settle such sales and may use securities received from us to close out or hedge any related short positions. We may also loan or pledge securities covered by this prospectus and an applicable prospectus supplement to third parties, who may sell the loaned securities or, in an event of default in the case of a pledge, sell the pledged securities pursuant to this prospectus and the applicable prospectus supplement or pricing supplement, as the case may be.

If indicated in an applicable prospectus supplement, we may sell shares of our common stock under a newly established direct stock purchase and dividend reinvestment plan. The terms of any such plan will be set forth in the applicable prospectus supplement.

A prospectus supplement with respect to each series of securities will state the terms of the offering of the securities, including:

The offer and sale of the securities described in this prospectus by us and/or the selling securityholders or the underwriters or the third parties described above may be effected from time to time in one or more transactions, including privately negotiated transactions, either:

The selling securityholders may offer our securities in one or more offerings, and if required by applicable law or in connection with an underwritten offering, pursuant to one or more prospectus supplements, and any such prospectus supplement will set forth the terms of the relevant offering as described above. To the extent our securities offered by a selling securityholder pursuant to a prospectus supplement remain unsold, the selling securityholder may offer those securities on different terms pursuant to another prospectus supplement. Sales by the selling securityholders may not require the provision of a prospectus supplement.

In addition to the foregoing, each of the selling securityholders may offer our securities at various times in one or more of the following transactions: through short sales, derivative and hedging transactions; by pledge to secure debts and other obligations; through offerings of securities exchangeable, convertible or exercisable for our securities; under forward purchase contracts with trusts, investment companies or other entities (which may, in turn, distribute their own securities); through distribution to its members, partners or shareholders; in exchange or over-the-counter market transactions; and/or in private transactions.

Each of the selling securityholders also may resell all or a portion of our securities that the selling securityholder owns in open market transactions in reliance upon Rule 144 under the Securities Act provided the selling securityholder meets the criteria and conforms to the requirements of Rule 144.

Any public offering price and any fees, discounts, commissions, concessions or other items constituting compensation allowed or reallowed or paid to underwriters, dealers, agents or remarketing firms may be changed from time to time. Underwriters, dealers, agents and remarketing firms that participate in the distribution of the offered securities may be “underwriters” as defined in the Securities Act. Any discounts or commissions they receive from us and/or the selling securityholders and any profits they receive on the resale of the offered securities may be treated as underwriting discounts and commissions under the Securities Act. We will identify any underwriters, agents or dealers and describe their fees, commissions or discounts in the applicable prospectus supplement or pricing supplement, as the case may be.

If underwriters are used in a sale, they will acquire the offered securities for their own account. The underwriters may resell the offered securities in one or more transactions, including negotiated transactions. We and/or the selling securityholders may offer the securities to the public either through an underwriting syndicate represented by one or more managing underwriters or through one or more underwriter(s). The underwriters in any particular offering will be identified in the applicable prospectus supplement or pricing supplement, as the case may be.

Unless otherwise specified in connection with any particular offering of securities, the obligations of the underwriters to purchase the offered securities will be subject to certain conditions contained in an underwriting agreement that we and/or the selling securityholders will enter into with the underwriters at the time of the sale to them. The underwriters will be obligated to purchase all of the securities of the series offered if any of the securities are purchased, unless otherwise specified in connection with any particular offering of securities. Any initial offering price and any discounts or concessions allowed, reallowed or paid to dealers may be changed from time to time.

We and/or the selling securityholders may designate agents to sell the offered securities. Unless otherwise specified in connection with any particular offering of securities, the agents will agree to use their best efforts to solicit purchases for the period of their appointment. We and/or the selling securityholders may also sell the offered securities to one or more remarketing firms, acting as principals for their own accounts or as agents for us and/or the selling securityholders. These firms will remarket the offered securities upon purchasing them in accordance with a redemption or repayment pursuant to the terms of the offered securities. A prospectus supplement or pricing supplement, as the case may be will identify any remarketing firm and will describe the terms of its agreement, if any, with us and/or the selling securityholders, and its compensation.

In connection with offerings made through underwriters or agents, we and/or the selling securityholders may enter into agreements with such underwriters or agents pursuant to which we receive our outstanding securities in consideration for the securities being offered to the public for cash. In connection with these arrangements, the underwriters or agents may also sell securities covered by this prospectus to hedge their positions in these outstanding securities, including in short sale transactions. If so, the underwriters or agents may use the securities received from us under these arrangements to close out any related open borrowings of securities.

We and/or the selling securityholders may sell the offered securities to dealers as principals. We and/or the selling securityholders may negotiate and pay dealers’ commissions, discounts or concessions for their services. The dealer may then resell such securities to the public either at varying prices to be determined by the dealer or at a fixed offering price agreed to with us at the time of resale. Dealers engaged by us may allow other dealers to participate in resales.

We and/or the selling securityholders may choose to sell the offered securities directly to multiple purchasers or a single purchaser. In this case, no underwriters or agents would be involved.

Direct sales to investors or our stockholders may be accomplished through subscription offerings or through stockholder subscription rights distributed to stockholders. In connection with subscription offerings or the distribution of stockholder subscription rights to stockholders, if all of the underlying securities are not subscribed for, we may sell any unsubscribed securities to third parties directly or through underwriters or agents. In addition, whether or not all of the underlying securities are subscribed for, we may concurrently offer additional securities to third parties directly or through underwriters or agents. If securities are to be sold through stockholder subscription rights, the stockholder subscription rights will be distributed as a dividend to the stockholders for which they will pay no separate consideration. The prospectus supplement with respect to the offer of securities under stockholder purchase rights will set forth the relevant terms of the stockholder subscription rights, including:

We and/or the selling securityholders may agree to indemnify underwriters, dealers, agents and remarketing firms against certain civil liabilities, including liabilities under the Securities Act and to make contribution to them in connection with those liabilities. Underwriters, dealers, agents and remarketing firms, and their affiliates, may engage in transactions with, or perform services for us, and our affiliates, in the ordinary course of business, including commercial banking transactions and services.

Each series of securities will be a new issue of securities and will have no established trading market, other than our class A common stock, which is listed on the NYSE. Any shares of our class A common stock sold pursuant to a prospectus supplement will be listed on the NYSE, subject to official notice of issuance. Any underwriters to whom we and/or the selling securityholders sell securities for public offering and sale may make a market in the securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The securities, other than the class A common stock, may or may not be listed on a national securities exchange, and any such listing if pursued will be described in the applicable prospectus supplement.

To facilitate the offering of the securities, certain persons participating in the offering may engage in transactions that stabilize, maintain, or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover the over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these

persons may stabilize or maintain the price of the debt securities by bidding for or purchasing debt securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

Unless otherwise indicated in the applicable prospectus supplement, certain legal matters will be passed upon us by Simpson Thacher & Bartlett LLP, New York, New York, and, with respect to matters of Maryland law, by Venable LLP, Baltimore, Maryland. An investment vehicle comprised of several partners of Simpson Thacher & Bartlett LLP, members of their families, related persons and others own interest representing less than 1% of the capital commitments of funds affiliated with Blackstone. If the validity of any securities is also passed upon by counsel for the underwriters, dealers or agents of an offering of those securities, that counsel will be named in the applicable prospectus supplement.

The consolidated financial statements of Capital Trust, Inc. appearing in Capital Trust’s Annual Report on Form 10-K for the year ended December 31, 2012 (including the schedule appearing therein), and the effectiveness of Capital Trust’s internal control over financial reporting as of December 31, 2012 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

The statement of revenues and certain operating expenses of West Coast Office Portfolio incorporated in this prospectus by reference from Blackstone Mortgage Trust, Inc.’s Current Report on Form 8-K, filed with the SEC on July 26, 2013, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report (which report expresses an unqualified opinion and includes an explanatory paragraph referring to the purpose and basis of presentation of the statement) which is incorporated herein by reference. Such statement of revenues and certain operating expenses have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

The statement of revenues and certain operating expenses of West Coast Office Park incorporated in this prospectus by reference from Blackstone Mortgage Trust, Inc.’s Current Report on Form 8-K, filed with the SEC on July 26, 2013, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in the report (which report expresses an unqualified opinion and includes an explanatory paragraph referring to the purpose and basis of presentation of the statement) which is incorporated herein by reference. Such statement of revenues and certain operating have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any materials we have filed with the SEC at the SEC’s Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. The SEC also maintains a web site at http://www.sec.gov that contains reports, proxy and information statements and other information concerning issuers that file electronically with the SEC, including us. Our class A common stock is listed and traded on the New York Stock Exchange. We also maintain an internet site at http://www.blackstonemortgagetrust.com that contains information concerning us. The information contained or referred to on our website is not incorporated by reference in this prospectus and is not a part of this prospectus.

We have filed with the SEC a registration statement on Form S-3 under the Securities Act to register the securities being offered in this prospectus. This prospectus, which constitutes part of the registration statement, does not contain all of the information set forth in the registration statement or the exhibits and schedules to the registration statement. For further information regarding us and our securities, please refer to the registration statement and the documents filed or incorporated by reference as exhibits to the registration statement. You may

obtain the registration statement and its exhibits from the SEC as indicated above or from us. Statements contained in this prospectus or any prospectus supplement as to the contents of any contract or other document that is filed or incorporated by reference as an exhibit to the registration statement are not necessarily complete and we refer you to the full text of the contract or other document filed or incorporated by reference as an exhibit to the registration statement.

The SEC allows us to “incorporate by reference” the information we file with the SEC, which means that we can disclose important information to you by referring you to those filed documents. The information incorporated by reference is considered to be part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information.

The following documents, which have been filed with the SEC (File No. 001-14788), are incorporated herein by reference:

All documents subsequently filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus and prior to the termination of the offering are deemed incorporated by reference into this prospectus and a part hereof from the date of filing of those documents. Notwithstanding the foregoing, information furnished under Items 2.02 and 7.01 of our current reports on Form 8-K, including the related exhibits, is not incorporated by reference in this registration statement. Any statement contained in any document incorporated by reference shall be deemed to be amended, modified or superseded for the purposes of this prospectus to the extent that a statement contained in this prospectus, any prospectus supplement or a later document that is or is considered to be incorporated by reference herein amends, modifies or supersedes such statement. Any statements so amended, modified or superseded shall not be deemed to constitute a part of this prospectus, except as so amended, modified or superseded.

We will provide without charge to each person to whom this prospectus is delivered, upon written or oral request of such person, a copy of any or all of the documents referred to above which have been or may be incorporated by reference into this prospectus. Requests for such documents should be directed to:


Citigroup		BofA Merrill Lynch		J.P. Morgan		Wells Fargo Securities		Morgan Stanley


	Page
About This Prospectus Supplement		ii
Forward-Looking Statements		iii
Summary		S-1
Risk Factors		S-5
Use of Proceeds		S-11
Capitalization		S-12
Description of Capital Stock		S-14
Underwriting		S-22
Material United States Federal Income Tax Considerations		S-29
Legal Matters		S-53
Experts		S-53
Where You Can Find More Information		S-53
Incorporation of Certain Documents by Reference		S-54


About This Prospectus			1
Blackstone Mortgage Trust, Inc.			2
Risk Factors			3
Forward-Looking Information			4
Use of Proceeds			6
Ratios of Earnings to Fixed Charges and Earnings to Combined Fixed Charges and Preferred Stock Dividends			7
Description of Capital Stock			8
Description of Depositary Shares			17
Description of Debt Securities			20
Description of Warrants			28
Description of Subscription Right			29
Description of Purchase Contracts			30
Description of Units			31
Book-Entry Issuance			32
Material United States Federal Income Tax Considerations			35
Plan of Distribution			58
Legal Matters			63
Experts			63
Where You Can Find More Information			63


	As of March 31, 2015
	Actual			As Adjusted(1)(2)			Pro Forma Adjusted
	(in thousands, except share and per share data)
Cash:		(unaudited)
Cash and cash equivalents	$	18,474		$	320,324		$	18,474
Restricted cash		26,890			26,890			26,890

Total cash	$	45,364		$	347,214		$	45,364

Debt:
Revolving repurchase facilities	$	2,241,630		$	2,241,630		$	2,233,776
Wells Fargo facility		—			—			3,771,784
Asset-specific repurchase agreements		407,203			407,203			407,203
Loan participations sold		708,845			708,845			708,845
5.25% Convertible Senior Notes due 2018		162,460			162,460			162,460

Total debt		3,520,138			3,520,138			7,284,068

Equity:
Class A common stock, $0.01 par value per share, 200,000,000 shares authorized, 58,451,077 shares issued and outstanding actual, 91,451,077 shares issued and outstanding as adjusted (3)		585			685			915
Additional paid-in capital		2,030,760			2,332,510			3,015,618
Accumulated other comprehensive loss		(31,756	)		(31,756	)		(31,756	)
Accumulated deficit		(542,654	)		(542,654	)		(542,654	)

Total Blackstone Mortgage Trust, Inc. stockholders’ equity		1,456,935			1,758,785			2,442,123

Non-controlling interests		45,763			45,763			45,763

Total equity		1,502,698			1,804,548			2,487,886

Total capitalization	$	5,022,836		$	5,324,686		$	9,771,954


	Page
About This Prospectus		1
Blackstone Mortgage Trust, Inc.		2
Risk Factors		3
Forward-Looking Information		4
Use of Proceeds		6
Ratios of Earnings to Fixed Charges and Earnings to Combined Fixed Charges and Preferred Stock Dividends		7
Description of Capital Stock		8
Description of Depositary Shares		17
Description of Debt Securities		20
Description of Warrants		28
Description of Subscription Rights		29
Description of Purchase Contracts		30
Description of Units		31
Book-Entry Issuance		32
Material United States Federal Income Tax Considerations		35
Plan of Distribution		58
Legal Matters		63
Experts		63
Where You Can Find More Information		63


Underwriter	Number of Shares
Citigroup Global Markets Inc.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
J.P. Morgan Securities LLC
Wells Fargo Securities, LLC
Morgan Stanley & Co. LLC

Total		10,000,000