EXHIBIT 4.2

DESCRIPTION OF THE REGISTRANT’S SECURITIES

REGISTERED PURSUANT TO SECTION 12

OF THE SECURITIES EXCHANGE ACT OF 1934

Our common stock is the only class of our securities that is registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The following description of our common stock is a summary and does not purport to be complete. It is subject to and qualified in its entirety by reference to our Amended and Restated Certificate of Incorporation (the “Certificate of Incorporation”) and our Amended and Restated Bylaws (the “Bylaws”), each of which are incorporated by reference as an exhibit to the Annual Report on Form 10-K of which this Exhibit 4.2 is a part.

General

Our authorized common stock consists of 150,000,000 shares, $0.01 par value per share. As of December 31, 2021, there were 39,203,747 shares of our common stock issued and 37,713,903 shares of our common stock outstanding. The authorized but unissued shares of our common stock will be available for future issuance without stockholder approval, unless otherwise required by applicable law or the rules of any applicable securities exchange. All of our issued and outstanding shares of common stock are validly issued, fully paid and non-assessable.

Subject to the rights and preferences granted to holders of our preferred stock then outstanding, and except with respect to voting rights, conversion rights and certain distributions of our capital stock, holders of our common stock rank equally with respect to distributions and have identical rights, preferences, privileges and restrictions, including the right to attend meetings and receive any information distributed by us with respect to such meetings.

Dividends. Holders of our common stock are equally entitled to receive ratably such dividends as may be declared from time to time by our board of directors out of legally available funds. In no event will any stock dividends or stock splits or combinations of stock be declared or made on common stock unless the shares of common stock at the time outstanding are treated equally and identically, provided that, in the event of a dividend of common stock, shares of common stock shall only be entitled to receive shares of common stock. The ability of our board of directors to declare and pay dividends on our common stock is subject to the laws of the state of Delaware, applicable federal and state banking laws and regulations, and the terms of any senior securities (including preferred stock) we may then have outstanding. Our principal source of income is dividends that are declared and paid by Byline Bank on its capital stock. Therefore, our ability to pay dividends is dependent upon the receipt of dividends from Byline Bank. Our Series B preferred stock ranks senior to our common stock as to dividends and distributions upon the liquidation, dissolution or winding up of Byline.

Voting rights. Each holder of our common stock is entitled to one vote for each share of record held on all matters submitted to a vote of stockholders, except as otherwise required by law and subject to the rights and preferences of the holders of any outstanding shares of our preferred stock. Holders of our common stock are not entitled to cumulative voting in the election of directors. Directors are elected by a plurality of the votes cast.

Liquidation rights. In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in all of our assets remaining after payment of liabilities, including, but not limited to, the liquidation preference of any then outstanding preferred stock. Because we are a bank holding company, our rights and the rights of our creditors and stockholders to receive the assets of any subsidiary upon liquidation or recapitalization may be subject to prior claims of our subsidiary’s creditors, except to the extent that we may be a creditor with recognized claims against our

EXHIBIT 4.2

subsidiary. Our Series B preferred stock ranks senior to our common stock as to dividends and distributions upon the liquidation, dissolution or winding up of Byline.

Preemptive and other rights. Holders of our common stock are not entitled to any preemptive, subscription or redemption rights, and no sinking fund will be applicable to our common stock.

Authorized but Unissued Capital Stock

The Delaware General Corporation Law (the “DGCL”) does not generally require stockholder approval for the issuance of authorized shares. These additional shares may be used for a variety of corporate purposes, including future public offerings, to raise additional capital or to facilitate acquisitions. However, the listing requirements of the NYSE, which would apply so long as the common stock remains listed on the NYSE, require stockholder approval of certain issuances equal to or exceeding 20% of the then outstanding voting power or then outstanding number of shares of common stock.

One of the effects of the existence of unissued and unreserved common stock or preferred stock may be to enable our board of directors to issue shares to persons friendly to current management, which issuance could render more difficult or discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise, and thereby protect the continuity of our management and possibly deprive our stockholders of opportunities they may believe are in their best interests or in which they may receive a premium for their common stock over the market price of the common stock.

Anti-Takeover Provisions in our Certificate of Incorporation and Bylaws

Business Combination Statute. We have elected to opt out of Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, subject to certain exceptions.

Federal banking law. The ability of a third party to acquire our stock is also limited under applicable U.S. banking laws, including regulatory approval requirements. The BHC Act requires any “bank holding company” to obtain the approval of the Federal Reserve before acquiring, directly or indirectly, more than 5% of our outstanding common stock. Any “company” (as defined in the BHC Act) other than a bank holding company is required to obtain the approval of the Federal Reserve before acquiring “control” of us. “Control” generally means (i) the ownership or control of 25% or more of a class of voting securities, (ii) the ability to elect a majority of the directors or (iii) the ability otherwise to exercise a controlling influence over management and policies. A person, other than an individual or a qualified family partnership, that controls us for purposes of the BHC Act is subject to regulation and supervision as a bank holding company under the BHC Act. In addition, under the Change in Bank Control Act of 1978, as amended, and the Federal Reserve’s regulations thereunder, any person, either individually or acting through or in concert with one or more persons, is required to provide notice to the Federal Reserve prior to acquiring, directly or indirectly, 10% or more of our outstanding common stock (or any other class of our voting securities).

Requirements for advance notification of stockholder nominations and proposals. Our Bylaws establish advance notice procedures with respect to stockholder proposals and nomination of candidates for election as directors. These procedures provide that notice of such stockholder proposal must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information required to be provided by our Bylaws.

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Limits on written consents. Our Certificate of Incorporation provides that any action to be taken by the stockholders that the stockholders are required or permitted to take must be effected at a duly called annual or special meeting of stockholders. Our stockholders are not permitted to take action by written consent.

Limits on special meetings. Subject to the rights of the holders of any series of preferred stock, special meetings of the stockholders may be called only by (i) our board of directors, (ii) the Chairperson of the board of directors, (iii) our Chief Executive Officer, (iv) our President or (v) our Executive Vice President.

Amending our Certificate of Incorporation and Bylaws

Our Certificate of Incorporation may be amended or altered in any manner provided by the DGCL. Our Bylaws may be adopted, amended, altered or repealed by stockholders only upon the affirmative vote of holders of a majority of the shares of our common stock present in person or represented by proxy at the meeting and entitled to vote thereon. Additionally, our Certificate of Incorporation provides that our Bylaws may be amended, altered or repealed by our board of directors by a majority vote.

Sole and Exclusive Forum

Our Bylaws provide that, unless we consent in writing to an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, employees or agents to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the DGCL, our Certificate of Incorporation or our Bylaws or (iv) any action asserting a claim that is governed by the internal affairs doctrine. Any person purchasing or otherwise acquiring any interest in any shares of our capital stock shall be deemed to have notice of and to have consented to this provision of our Bylaws. This choice of forum provision may have the effect of discouraging lawsuits against us and our directors, officers, employees and agents. However, the exclusive forum clause described above shall not apply to suits brought to enforce a duty or liability created by federal law, including the Exchange Act and the Securities Act, for which the federal courts have exclusive jurisdiction. To the extent the exclusive forum provision restricts the courts in which our stockholders may bring claims arising under the Securities Act, there is uncertainty as to whether a court would enforce such provision. Our stockholders will not be deemed to have waived compliance with the federal securities laws and the rules and regulations thereunder.

Indemnification and Limitation of Liability

Our Bylaws provide generally that we will indemnify and hold harmless, to the full extent permitted by law, our directors, officers, employees and agents, as well as other persons who have served as our directors, officers, employees or agents and other persons who serve or have served at our request at another corporation, limited liability company, public limited company, partnership, joint venture, trust, employee benefit plan, fund or other enterprise in connection with any actual or threatened action, suit or proceeding, subject to limited exceptions. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers and controlling persons, we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. Finally, our ability to provide indemnification to our directors and officers is limited by federal banking laws and regulations.

Our Certificate of Incorporation limits, to the full extent permitted by law, the personal liability of our directors in actions brought on our behalf or on behalf of our stockholders for monetary

EXHIBIT 4.2

damages as a result of a director’s breach of fiduciary duty while acting in a capacity as a director. Our Certificate of Incorporation does not eliminate or limit our right or the right of our stockholders to seek injunctive or other equitable relief not involving monetary damages.

Listing

Our common stock is listed on the NYSE under the symbol “BY”.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC.