FX.co ★ U.S. 4-Week Bill Auction Yield Edges Up to 3.85%, Extending Short-Term Rate Rise

The yield on the U.S. 4-week Treasury bill inched higher at the latest auction, rising to 3.850% from the previous level of 3.820%. The updated figure, as of 24 September 2026, underscores a modest but continuing uptick in very short-term government borrowing costs.

This increase, though slight, may signal persistent tightness in short-term funding conditions or a gradual adjustment in market expectations for near-term interest rates. The 4-week bill, a key benchmark for liquidity and cash management instruments, often reflects investor sentiment about the immediate rate path and demand for ultra-short maturities.

With the current auction result pushing the yield 3 basis points above the prior reading, market participants will be watching upcoming bill sales and policy signals closely for further confirmation of the direction of short-term U.S. rates.