Strategy. The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (Component Securities) of ICE BofA Long US Treasury Principal STRIPS Index (the Underlying Index). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC (PIMCO) believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. Fixed Income Instruments include bonds, debt securities and other similar instruments issued … Show more… The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (Component Securities) of ICE BofA Long US Treasury Principal STRIPS Index (the Underlying Index). The Fund may invest the remainder of its assets in Fixed Income Instruments that are not Component Securities, but which Pacific Investment Management Company LLC (PIMCO) believes will help the Fund track its Underlying Index, as well as in cash and investment grade, liquid short-term instruments, forwards or derivatives, such as options, futures contracts or swap agreements, and shares of affiliated bond funds. Fixed Income Instruments include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The average portfolio duration of this Fund will closely correspond to the portfolio duration of the securities comprising its Underlying Index, as calculated by PIMCO, which as of September 30, 2025 was 28.00 years. Duration is a measure used to determine the sensitivity of a securitys price to changes in interest rates. The longer a securitys duration, the more sensitive it will be to changes in interest rates. The Underlying Index is an unmanaged index comprised of long maturity Separate Trading of Registered Interest and Principal of Securities (STRIPS) representing the final principal payment of U.S. Treasury bonds. The principal STRIPS comprising the Underlying Index must have 25 years or more remaining term to final maturity and must be stripped from U.S. Treasury bonds having at least $1 billion in outstanding face value. As of September 30, 2025, there were 20 issues in the Underlying Index. Index constituents are capitalization-weighted based on the security prices times an assumed face value of $1 billion per constituent security. The Underlying Index is rebalanced quarterly on March 31, June 30, September 30 and December 31, based on information available up to and including the third business day before the last business day of the rebalancing month. Securities that no longer meet the qualifying criteria during the course of the quarter remain in the Underlying Index until the next quarterly rebalancing date at which point they are dropped from the Underlying Index. It is not possible to invest directly in the Underlying Index. The Underlying Index does not reflect deductions for fees, expenses or taxes. PIMCO uses an indexing approach in managing the Funds investments. The Fund employs a representative sampling strategy in seeking to achieve its investment objective. In using this strategy, PIMCO seeks to invest in a combination of Component Securities and other instruments, or in Component Securities but in different proportions as compared to the weighting of the Underlying Index, such that the portfolio effectively provides exposure to the Underlying Index. In using a representative sampling strategy, the Fund may not track its Underlying Index with the same degree of accuracy as a fund that replicates the composition and weighting of the Underlying Index. Unlike many investment companies, the Fund does not attempt to outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies. The Fund may invest in derivative instruments, such as options, futures contracts or swap agreements. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs). The total return sought by the Fund consists of income earned on the Funds investments, plus capital appreciation, if any, which generally arises from decreases in interest rates. Show less