If I invested $10,000 in U.S. 3-month Treasury bills (rolled) in Jan 2015
It would be worth $12,932 by Nov 2026 — 1.29×, or 2.2% a year.
Data: index computed from U.S. Treasury par yields; inflation: BLS CPI-U. Historical illustration, not financial advice; ignores fees, storage and taxes. Details
How to read this example
A wealth index we compute from official U.S. Treasury Daily Treasury Par Yield Curve Rates for the 3-month tenor. The index starts at 100 in the first month and then compounds monthly at the prior month’s average daily 3-month par yield divided by 12. It is an approximation of rolling short-term Treasury bills, not a published Treasury total-return product. In this example, $10,000 bought 45.9643 index units at the Jan 2015 level of 217.56. At the Nov 2026 level of 281.34, that quantity is worth $12,932. In Jan 2015 dollars, that is about $8,970 (0.90× after inflation).
Frequently asked questions
How much would $10,000 in U.S. 3-month Treasury bills (rolled) in Jan 2015 be worth now?
About $12,932 as of Nov 2026, which is 1.29 times the original amount, or a 29.3% total return (2.2% annualized). That uses the official series cited below and ignores costs and taxes.
What is that in Jan 2015 dollars?
About $8,970, after adjusting with BLS CPI-U. Consumer prices rose 1.44× over the span, so the real multiple is 0.90× (-0.9% real CAGR).
What if I had invested $10,000 in January 2000?
About $17,097 as of Nov 2026 (1.71×, 2.0% CAGR), on the same method.
What if I also added $100 a month starting after Jan 2015?
You would have contributed $24,200 in total, and the holding would be worth about $29,949 as of Nov 2026 (1.24× the money put in; money-weighted return 2.5%). Contributions are applied at each later monthly observation.
Is this the same as buying an ETF or a house?
No. This is a simplified monthly compounding of official 3-month Treasury yields, not a broker-sold bill ladder or a bond fund.
Sources, formula & caveats
Not financial advice. This is a historical thought experiment, not a recommendation to buy or sell anything. Past performance is not indicative of future results. Figures use a wealth index we compute from official U.S. Treasury 3-month par yields, compounded monthly. It is not a published Treasury total-return index and ignores taxes and purchase/sale spreads. A real investment would have returned something different.
Start month is the first observation on or after the date you enter. Years use a 365.25-day convention. Inflation uses BLS CPI-U, all items, not seasonally adjusted.
- Source: U.S. Department of the Treasury, Daily Treasury Par Yield Curve Rates (3-month). This site is not affiliated with or endorsed by the Treasury.
- License and terms: U.S. government work. Treasury Fiscal Data: “The data is offered free, without restriction, and available to copy, adapt, redistribute, or otherwise use for non-commercial or commercial purposes.” The 3-month wealth index on this site is a derived series computed from those official yields, not a published Treasury total-return index.
- File: https://home.treasury.gov/resource-center/data-chart-center/interest-rates/pages/xml?data=daily_treasury_yield_curve&field_tdr_date_value={year}.
- Series in this file: Jan 1990 through Nov 2026 (443 months). Fetched 2026-11-10.