SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) is an exchange-traded fund that seeks to provide investment results, before fees and expenses, corresponding generally to the price and yield performance of the Bloomberg 3-12 Month U.S. Treasury Bill Index. The fund primarily invests in publicly issued U.S. Treasury Bills with remaining maturities greater than or equal to 3 months and less than 12 months; these securities are rated investment grade, denominated in U.S. dollars, and feature fixed rates. The index is market capitalization weighted, excluding securities held in the Federal Reserve System Open Market Account, and the fund employs a representative sampling technique to track it while maintaining characteristics such as an option-adjusted duration of approximately 0.42 years and holdings concentrated in Aa-rated securities.
BILS operates within the ultrashort bond segment of the fixed income market, targeting investors seeking low-risk, short-duration exposure to U.S. government debt as a cash alternative or parking vehicle amid interest rate fluctuations. The ETF distributes dividends monthly, with a trailing twelve-month yield around 4.23% and a gross expense ratio of 0.1356%; as of late 2025, it manages approximately $3.86 billion in assets under management with about 29 holdings.
Launched on September 23, 2020, by State Street Global Advisors, a division of State Street Corporation headquartered in Boston, Massachusetts, the fund was originally named SPDR Bloomberg Barclays 3-12 Month T-Bill ETF prior to October 31, 2021, reflecting a rebranding aligned with the index's name change from Bloomberg Barclays 3-12 Month U.S. Treasury Bill Index on August 24, 2021. It lists on NYSE Arca and serves institutional and retail investors focused on capital preservation and yield in the U.S. Treasury bill market, with no international geographic operations beyond U.S.-denominated securities. No major acquisitions, funding rounds, partnerships, or strategic shifts have been reported in the last 1-2 years; recent activity centers on sustained asset growth and monthly rebalancing on the last business day of each month.