Summary Prospectus FlexShares^® STOXX^® Global Broad Infrastructure Index Fund

October 7, 2013 Ticker: NFRA Stock Exchange: NYSE Arca

Before you invest, you may want to review the Fund’s complete Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s complete Prospectus and other information about the Fund online at www.flexshares.com/prospectus. You can also get this information at no cost by calling 1-855-FLEXETF (1-855-353-9383) or by sending an e-mail request to info@flexshares.com. The Fund’s complete Prospectus and Statement of Additional Information, both dated October 7, 2013, as supplemented, are incorporated by reference into this summary prospectus and may be obtained, free of charge, at the website, phone number or e-mail address noted above.

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the STOXX^® Global Broad Infrastructure Index (the “Underlying Index”).

Fees And Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You will also incur usual and customary brokerage commissions when buying or selling shares of the Fund in the secondary market, which are not reflected in the example that follows:

Shareholder Fees (fees paid directly from your investment)
None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.47%
Distribution (12b-1) Fees	0.00%
Other Expenses(1)	0.01%
Total Annual Fund Operating Expenses	0.48%
Expense Reimbursement(2)	0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.47%

⁽¹⁾  Under the Fund’s Investment Advisory Agreement, Northern Trust Investments, Inc. (“NTI” or “Investment Adviser”) is responsible for most of the operating expenses of the Fund. However, the Investment Adviser is not responsible for the following expenses: interest expenses, brokerage commissions and other trading expenses, fees and expenses of the independent trustees and their independent legal counsel, taxes and other extraordinary costs such as litigation and other expenses not incurred in the ordinary course of business. Other expenses are estimated for the current fiscal year as the Fund has not commenced operations as of the date of this Prospectus.

⁽²⁾  NTI has contractually agreed to reimburse the fees and expenses of the Trust’s independent trustees and their independent legal counsel until October 7, 2014. The Fund’s Board of Trustees may terminate the contractual arrangement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000

in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	$	48
3 Years	$	153

Portfolio Turnover. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. Portfolio turnover may vary from year to year, as well as within a year.

Principal Investment Strategies

The Underlying Index reflects the performance of a selection of equity securities of infrastructure-related companies that are domiciled or traded in developed and emerging markets around the world (including the U.S.). The companies included in the Underlying Index derive at least 50% of their revenues from the ownership, development, construction, financing or operation of infrastructure assets, as determined by STOXX (the “Index Provider”) pursuant to its index methodology. Infrastructure assets are defined by the Index Provider as the physical structures and networks upon which the operation, growth and development of a community depends, and include: (a) communication (cable and satellite, data centers, wireless, wireless towers and wireline); (b) energy (energy utilities and midstream energy); (c) government outsourcing/social (correctional facilities, hospitals and postal services); (d) transportation (air transportation, passenger transportation, rail transportation, road transportation and water transportation; and (e) utilities (waste management and water utilities). Constituents of the Underlying Index may include common and preferred stocks, publicly-traded units of master limited partnerships (“MLPs”), and real estate investment trusts (“REITs”). In addition to tracking the performance of the

www.flexshares.com

FlexShares^® STOXX^® Global Broad Infrastructure Index Fund Page 2

Underlying Index, the Investment Adviser also seeks to minimize portfolio turnover and tax inefficiencies.

As of September 19, 2013, the Underlying Index comprised 155 stocks with market capitalizations ranging from $97.47 million to $228.03 billion. As of the same date, the Underlying Index’s five largest constituents (by weighting) were AT&T Inc., Vodafone Group, Canadian National Railway Company, Verizon Communications and East Japan Railway Company. As of September 19, 2013, the top five countries (by weighting) represented in the Underlying Index were the United States (38%), Japan (11.6%), United Kingdom (10.6%), Canada (10.4%) and Germany (6.1%). The Underlying Index is governed by published, objective rules for security selection, exclusion, rebalancing and adjustments for corporate actions and is reconstituted on a semi-annual basis. The Index Provider’s index methodology and other factors will cause the composition of the Underlying Index to change over time.

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

NTI uses a representative sampling strategy to manage the Fund. “Representative sampling” is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. Securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. Funds that employ a representative sampling strategy may incur tracking error to a greater extent than a fund that seeks to replicate an index. “Replication” is an indexing strategy in which a fund invests in substantially all of the securities in its underlying index in approximately the same proportions as in the underlying index. The Fund reserves the right to use a replication indexing strategy if NTI determines that it is in the best interests of the Fund.

The Fund generally will invest under normal circumstances at least 80% of its total assets in the securities of the Underlying Index and in American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”) based on the securities in its Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts, options on futures contracts, forward currency contracts, options and swaps, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Underlying Index is sponsored by the Index Provider, an organization that is independent of the Fund and NTI. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. Additional information regarding the Index Provider is provided in the “More Information about Underlying Index and Index Provider section of the Prospectus.

The Fund is “non-diversified” under the Investment Company Act of 1940, as amended, and may invest more of its assets in fewer issuers than “diversified” funds.

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated.

Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), trading price, yield, total return and ability to meet its investment objective.

Asset Class Risk is the risk that securities in the Underlying Index or the Fund’s portfolio may underperform in comparison to the general securities markets or other asset classes.

Concentration Risk is the risk that, to the extent the Fund’s investments are concentrated in the securities of issuers in a particular region, country, market, industry, sector or asset class, the Fund may be subject to increased price volatility and may be more susceptible to adverse economic, market, political or regulatory occurrences affecting that region, country, market, industry, sector or asset class.

Counterparty Risk is the risk that a counterparty to a financial instrument may default on its payment obligation to the Fund. Such a default may cause the value of an investment in the Fund to decrease.

Currency Risk is the risk that foreign currencies will fluctuate in value relative to the U.S. dollar, adversely affecting the value of the Fund’s investments and its returns. Because the Fund’s NAV is determined on the basis of U.S. dollars, you may lose money if the local currency of a foreign market depreciates against the U.S. dollar, even if the market value of the Fund’s holdings appreciates.

Derivatives Risk is the risk of investing in derivative instruments, including liquidity, interest rate, market, credit, counterparty and management risks, as well as the risk of mispricing or improper valuation. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Fund could lose more than the principal amount invested.

www.flexshares.com

FlexShares^® STOXX^® Global Broad Infrastructure Index Fund Page 3

Emerging Markets Risk is the risk that markets of emerging market countries are less developed and less liquid, subject to greater price volatility and generally subject to increased economic, political, regulatory and other uncertainties than more developed markets.

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile than other asset classes, and includes the risk that preferred stocks and REITs will be more sensitive to interest rate changes.

Foreign Securities Risk is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in U.S. securities, due to less liquid markets, and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments also may impose limits on investment and repatriation and impose taxes. Any of these events could cause the value of the Fund’s investments to decline.

Infrastructure-Related Companies Risk is the risk that the Fund is subject to the risks associated with investment in infrastructure-related companies in addition to the general risk of the stock market. Risks associated with infrastructure-related companies include: (a) realized revenue volume may be significantly lower than projected and/or there will be cost overruns; (b) infrastructure project sponsors will alter their terms making a project no longer economical; (c) macroeconomic factors such as low gross domestic product (“GDP”) growth or high nominal interest rates will raise the average cost of infrastructure funding; (d) government regulation may affect rates charged to infrastructure customers; (e) government budgetary constraints will impact infrastructure projects; (f) special tariffs will be imposed; and (g) changes in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks include environmental damage due to a company’s operations or an accident, a natural disaster, changes in market sentiment towards infrastructure and terrorist acts. Any of these events could cause the value of the Fund’s investments in infrastructure-related companies to decline.

Issuer Risk is the risk that changes in the financial condition of an issuer or counterparty, changes in specific economic or political conditions that affect a particular type of security or issuer, and changes in general economic or political conditions can affect a security’s or instrument’s credit quality or value.

Management Risk is the risk that the representative sampling strategy used by NTI may fail to produce the intended results.

Market Risk is the risk that the Fund could lose money over short periods due to short-term market movements and over longer periods during market downturns.

Market Segment Risk is the risk that concentrating in a particular segment of the market will generally be more volatile than investing more broadly. Any market price movements, regulatory or technological changes, or economic conditions affecting infrastructure–related companies may have a significant impact on the Fund’s performance.

Market Trading Risk is the risk that the Fund faces because its shares are listed on a securities exchange, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Mid Cap Stock Risk is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market.

MLP Risk is the risk that accompanies an investment in MLP units. Investing in MLPs involves certain risks related to investing in the underlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs that concentrate in a particular industry or a particular geographic region are subject to risks associated with such industry or region. The benefit derived from the Fund’s investment in MLPs is largely dependent on the MLPs being treated as partnerships for federal income tax purposes. If any of the MLPs owned by the Fund were treated as corporations for U.S. federal income tax purposes, the after-tax return to the Fund with respect to its investment in such MLPs would be materially reduced, which could cause a decline in the value of the Fund’s shares. The Fund must include its allocable share of the MLP’s taxable income in its taxable income, whether or not it receives a distribution of cash from the MLP. In such case, the Fund may have to liquidate securities to make required distributions to the Fund’s shareholders.

New Fund Risk is the risk that the Fund faces because it is a new fund. As a new fund, there can be no assurance that it will grow to or maintain an economically viable size, in which case it may experience greater tracking error to its Underlying Index than it otherwise would at higher asset levels, or it could ultimately liquidate. The Fund’s Distributor does not maintain a secondary market in the shares.

Non-Diversification Risk is the risk that Fund performance may depend on the performance of a small number of

www.flexshares.com

FlexShares^® STOXX^® Global Broad Infrastructure Index Fund Page 4

issuers because the Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers.

Passive Investment Risk is the risk that the Fund is not actively managed and NTI does not attempt to take defensive positions in any market conditions, including declining markets.

REIT Risk is the risk that the Fund’s investments may be affected by factors affecting REITs and the real estate sector generally. Investing in REITs involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. REITs whose underlying properties are concentrated in a particular industry or geographic region are also subject to risks affecting such industries and regions. By investing in REITs through the Fund, a shareholder will bear expenses of the REITs in addition to expenses of the Fund.

Small Cap Stock Risk is the risk that stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources, or may be dependent upon a small or inexperienced management group, and their securities may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk.

Tracking Error Risk is the risk that the Fund’s performance may vary substantially from the performance of the Underlying Index. The Fund employs a representative sampling strategy, and may incur tracking error to a greater extent than a fund that seeks to replicate an index.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Because the Fund has less than one full calendar year of performance, no performance information has been included.

Management

Investment Adviser and Portfolio Managers. Northern Trust Investments, Inc., an indirect subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Chad M. Rakvin, Senior Vice President of Northern Trust Investments, Inc., Shaun Murphy, Senior Vice President of Northern Trust Investments, Inc., and Jordan Dekhayser, Vice President of Northern Trust Investments, Inc., have each been managers of the Fund since its inception.

Purchase and Sale of Fund Shares

The Fund is an exchange-traded fund (commonly referred to as an “ETF”). Individual Fund shares may only be purchased and sold on a national securities exchange through a broker-dealer. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). The Fund will only issue or redeem shares that have been aggregated into blocks of 50,000 shares or multiples thereof (“Creation Units”) to authorized participants who have entered into agreements with the Fund’s distributor. The Fund will issue or redeem Creation Units in return for a basket of assets that the Fund specifies each day.

Tax Information

The Fund’s distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-exempt or tax-deferred arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-deferred accounts.

Payments to Brokers-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), NTI and its related companies may pay the intermediary for activities related to the marketing and promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

www.flexshares.com