FlexShares Disciplined Duration MBS Index Fund (MBSD) is subject to credit risk, which is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a TBA, repurchase or other transaction, to meet its payment or other financial obligations will adversely affect the value of the Fund’s investments and its returns. Changes in the credit rating of a debt security held by the Fund could have a similar effect. Debt extension risk is the risk that an issuer will exercise its right to pay principal on an obligation held by the Fund (such as a mortgage-backed security) later than expected. This may happen during a period of rising interest rates. Under these circumstances, the value of the obligation will decrease and the Fund will suffer from the inability to invest in higher yielding securities. Mortgage-backed pass-through securities risk is the risk of investing in mortgage-backed securities issued by a U.S. Agency. These securities may not be backed by the full faith and credit of the U.S. government. As interest rates rise, bond prices fall, reducing the value of fixed income investments.