American Century Zero Coupon 2020 Fund Investor Class (BTTTX) is a closed-end fixed income mutual fund managed by American Century Investments that seeks high current income by investing primarily in zero-coupon U.S. Treasury securities maturing in or around 2020; it offers shares through the Investor Class with ticker BTTTX, providing tax-exempt interest for qualified investors and focusing on intermediate-term government obligations with low credit risk. The fund's core offerings include a portfolio of stripped Treasury securities, such as STRIPS (Separate Trading of Registered Interest and Principal of Securities), designed for predictable cash flows and capital preservation; it targets conservative income-oriented investors, including retirement plans and tax-sensitive individuals, with geographic operations centered in the United States. Founded as part of American Century's lineup in the 1980s under the broader firm established in 1958 and headquartered in Kansas City, Missouri, the fund operates within the asset management industry, emphasizing fixed income segments without notable subsidiaries. In recent years, the fund underwent a significant maturity event around 2020, leading to liquidation and distribution of principal to shareholders as its target bonds redeemed; American Century Investments announced no new zero-coupon funds of similar vintage post-2020 amid shifting interest rate environments, with the firm instead expanding active fixed income strategies and ETF offerings through strategic partnerships like those enhancing sustainable investing capabilities.