Treasury bill yields increased relative to key short-term interest-rate benchmarks on October 7, 2026, driven by a sharp slowdown in U.S. money-market fund cash inflows and anticipation of expanded government debt supply. Data from TD Securities showed that capital entering U.S. money-market funds reached approximately $158 billion during the first three quarters of the year, reflecting a significant deceleration compared to the $823 billion registered in 2024 and $840 billion recorded in 2025.
This moderation in cash accumulation reduced a primary source of buying pressure for short-term government debt. While money-market funds remain net buyers, Investment Company Institute figures indicated that their Treasury bill holdings grew roughly 4% through August, down from an 18% expansion over all of last year.
Impact of Slowing Inflows on Short-Term Yields
The reduced demand from money funds pushed up Treasury bill yields relative to comparable overnight index swaps (OIS), which serve as a key benchmark reflecting Federal Reserve rate expectations. Analysts noted that without substantial inflows, money funds must carefully reconsider where to allocate capital.
The softer demand translated directly into higher pricing for short-term bills, as investors demanded a larger premium to hold them. U.S. 3-month bill yields rose nearly 10 basis points above 3-month OIS, reaching the widest spread since September 2024. For six-month maturities, the spread touched 12.5 basis points, marking its highest level since April 2025.
Nafis Smith, principal and head of taxable money markets at Vanguard, attributed the reduced money fund flows partly to the strength of the U.S. equity market. With the S&P 500 up 13% and the Nasdaq up 18% over the year, the incentive for investors to hold cash has diminished.
Broad Market Implications and Future Outlook
Analysts also cited expectations of heavy Treasury supply in the fourth quarter and potential further interest rate hikes from the Federal Reserve. Barclays estimated that the Treasury would issue approximately $225 billion of bills in October and another $160 billion in November.
Gennadiy Goldberg, head of U.S. rates strategy at TD Securities, expressed concern that the largest source of demand for bills is slowing while the Treasury aims to increase issuance at the front of the curve. If persistent, higher bill yields could tighten funding conditions, potentially pushing up repo rates and financing costs for dealers and market participants as funds shift cash from overnight repo markets into higher-yielding Treasury bills.
However, market experts suggest it is too early to raise alarms, as money fund inflows typically increase in the fourth quarter ahead of year-end liquidity needs. Growing uncertainty over future interest rates continues to contribute to higher bill yields, with U.S. rate futures pricing in additional rate moves over the coming years.
Frequently Asked Questions
What are money market funds?
Money market funds are a type of mutual fund that invests in highly liquid, near-term instruments such as cash, cash equivalent securities, and high-credit-rating debt-based securities like Treasury bills.
What is an overnight index swap (OIS)?
An overnight index swap is an interest rate swap where a fixed rate is exchanged against a predetermined floating rate, typically used as a gauge for market expectations of future central bank policy rates.
What is the repo market?
The repurchase agreement (repo) market is a short-term funding market where participants borrow and lend cash using securities, primarily government bonds, as collateral.
What is weighted average maturity (WAM)?
Weighted average maturity measures the average time until the securities in a fixed-income portfolio mature, weighted by the relative size of each security. Lower WAM indicates a shorter-dated portfolio designed to adapt to rising interest rate environments.
