Strategy. Under normal circumstances, the Fund invests at least 80% of its assets in bonds within its benchmark and portfolio tracking index, the Bloomberg U.S. Aggregate Bond Index (the Index). The Fund uses a sampling technique to create a portfolio that closely matches the overall investment characteristics of the Index (for example, duration, sector diversification and credit quality) without investing in all of the securities in its index. At times the Fund may purchase securities not held in the Index, but which Teachers Advisors, LLC (Advisors) believes have similar investment characteristics to securities held in its index. Generally, the Fund intends to invest in a wide spectrum of public, investment-grade, taxable debt securities denominated in U.S. dollars including government securities, as … Show more… Under normal circumstances, the Fund invests at least 80% of its assets in bonds within its benchmark and portfolio tracking index, the Bloomberg U.S. Aggregate Bond Index (the Index). The Fund uses a sampling technique to create a portfolio that closely matches the overall investment characteristics of the Index (for example, duration, sector diversification and credit quality) without investing in all of the securities in its index. At times the Fund may purchase securities not held in the Index, but which Teachers Advisors, LLC (Advisors) believes have similar investment characteristics to securities held in its index. Generally, the Fund intends to invest in a wide spectrum of public, investment-grade, taxable debt securities denominated in U.S. dollars including government securities, as well as mortgage-backed, commercial mortgage-backed and asset-backed securities. The Funds investments in mortgage-backed securities may include pass-through securities sold by private, governmental and government-related organizations and U.S. Government-sponsored enterprises (GSEs), to the extent that such instruments are held by the Index. The Fund may also invest in securities having a variable or floating interest rate. The Fund generally will invest in foreign securities denominated in U.S. dollars only to the extent they are included or eligible to be included in the Index. For purposes of the 80% investment policy, the term assets means net assets, plus the amount of any borrowings for investment purposes. The securities purchased by the Fund will mainly be high-quality instruments rated in the top four credit categories by a nationally recognized statistical rating organization (NRSRO) or deemed to be of the same quality by Advisors using its own credit quality analysis. The Fund may continue to hold instruments that were rated as high-quality when purchased, but which subsequently are downgraded to below-investment-grade status or have their ratings withdrawn by one or more rating agencies. Because the return of the Index is not reduced by investment and other operating expenses, the Funds ability to match the Index is negatively affected by the costs of buying and selling securities, as well as other fees and expenses. The use of the Index by the Fund is not a fundamental policy of the Fund and may be changed without shareholder approval. The Fund is classified as a diversified investment company, as defined under the Investment Company Act of 1940, as amended (the 1940 Act). However, the Fund may become non-diversified under the 1940 Act without the approval of Fund shareholders solely as a result of a change in relative market capitalization or index weighting of one or more constituents of its benchmark index, the Bloomberg U.S. Aggregate Bond Index, which the Fund seeks to track. Show less