Strategy. Under normal market conditions, the Fund invests at least 80% of its net assets in securities issued or guaranteed by the U.S. government, its agencies, or instrumentalities. The Fund currently targets an estimated portfolio duration of three (3) years or less. The Fund generally invests 50-80% of its assets in mortgage securities issued or guaranteed by the U.S. government, its agencies, or instrumentalities, including adjustable rate mortgage securities (ARMs) and collateralized mortgage obligations (CMOs), but the Fund also invests in direct obligations of the U.S. government (such as Treasury bonds, bills and notes) and in securities issued or guaranteed by the U.S. government, its agencies or instrumentalities, including government sponsored entities. All of the Funds principal investments are debt securities, … Show more… Under normal market conditions, the Fund invests at least 80% of its net assets in securities issued or guaranteed by the U.S. government, its agencies, or instrumentalities. The Fund currently targets an estimated portfolio duration of three (3) years or less. The Fund generally invests 50-80% of its assets in mortgage securities issued or guaranteed by the U.S. government, its agencies, or instrumentalities, including adjustable rate mortgage securities (ARMs) and collateralized mortgage obligations (CMOs), but the Fund also invests in direct obligations of the U.S. government (such as Treasury bonds, bills and notes) and in securities issued or guaranteed by the U.S. government, its agencies or instrumentalities, including government sponsored entities. All of the Funds principal investments are debt securities, including bonds, notes and debentures. In comparison to maturity (which is the date on which a debt instrument ceases and the issuer is obligated to repay the principal amount), duration is a measure of the expected price volatility of a debt instrument as a result of changes in market rates of interest, based on the weighted average timing of the instruments expected principal and interest payments and other factors. For purposes of calculating the Funds portfolio duration, the Fund includes the effect of interest rate/bond futures contracts and options on interest rate/bond futures contracts held by the Fund. Mortgage securities represent an interest in a pool of mortgage loans made by banks and other financial institutions to finance purchases of homes, commercial buildings and other real estate. As the underlying mortgage loans are paid off, investors receive periodic principal and interest payments as well as any unscheduled principal prepayments on the underlying mortgage loans. The mortgage securities purchased by the Fund include, but are not limited to, bonds and notes issued or guaranteed by the Government National Mortgage Association (Ginnie Mae) and U.S. government-sponsored entities, such as the Federal National Mortgage Association (Fannie Mae), and the Federal Home Loan Mortgage Corporation (Freddie Mac). Government agency or instrumentality issues have different levels of credit support. Ginnie Mae pass-through mortgage certificates are backed by the full faith and credit of the U.S. government. U.S. government-sponsored entities, such as Fannie Mae and Freddie Mac, may be chartered by Acts of Congress, but their securities are neither issued nor guaranteed by the U.S. government. Although the U.S. government has provided financial support to Fannie Mae and Freddie Mac, no assurance can be given that the U.S. government will continue to do so. The Fund may invest in obligations of other U.S. government-sponsored entities, which may be supported only by the credit of the issuing agency or instrumentality, such as securities issued by members of the Farm Credit System. The Fund may invest in mortgage dollar rolls. In a mortgage dollar roll, the Fund sells (or buys) mortgage securities for delivery on a specified date and simultaneously contracts to repurchase (or sell) substantially similar (same type, coupon, and maturity) securities on a future date. The Fund may also purchase or sell mortgage securities on a delayed delivery or forward commitment basis through the "to-be-announced" (TBA) market. With TBA transactions, the particular securities to be delivered must meet specified terms and standards. The Fund will invest only in covered mortgage dollar rolls or TBA transactions, meaning that the Fund designates liquid securities in its portfolio equal in value to the securities it will repurchase. The Fund invests in investment grade securities and investments or in unrated securities and investments that the Funds investment manager determines are of comparable quality. The Fund may invest in U.S. inflation-indexed securities issued by the U.S. government. To pursue its investment goal, the Fund may invest in certain interest rate-related derivative transactions, principally U.S. Treasury futures contracts and options on interest rate/bond futures. The use of these derivative transactions may allow the Fund to obtain net long or short exposures to selected interest rates or durations. These derivatives may be used to hedge risks associated with the Funds other portfolio investments and to manage the duration of the Funds portfolio. Show less