RatesOct 6, 2026, 10:22 AM ET

The 10-year yield is at its 2026 high while one-year rates fell: what does it mean for the cost of term?

Applies to:: SPX box spread, American-style box spread, Half box
Risk type:: Financing cost

Fact

The 10-year U.S. Treasury par yield was 5.31% on October 5 (5.28% on October 2, 5.24% on September 28). That is the highest value in the Treasury's daily series since the start of 2026.
The short end fell over the same week: 1 year 4.47% (4.59% on September 28), 6 months 4.30% (4.41%), 3 months 4.22% (4.28%).
The gap between 10 years and 3 months is 1.09 percentage points (0.96 on September 28).

Source: U.S. Treasury, Daily Treasury Par Yield Curve Rates (data as of October 5, 2026, checked October 6, 2026).

Our reading

Over the week the curve steepened: long-term money became more expensive, while money for up to a year became cheaper. The cost of a box is set by the part of the curve that matches its term, so a one-year box should be compared with one-year rates, not ten-year ones. Higher long-term yields matter more for mortgages and long-term loans. The latest ZMR is 4.85% (October 2, 363-day term); the next value comes after the October 9 close. What it will be cannot be said in advance.

What to check

For how long do you need the money, and which part of the curve should its cost be compared with?
Is the rate on your loan floating, or fixed for a term?
When does your structure expire, and at what rate could it be rolled?

Limits

Treasury yields are coupon-equivalent par yields; ZMR is a simple ACT/360 rate at the bid/ask midpoint, so subtracting one from the other gives only an approximate difference. The entry does not analyze why the curve moved; one week is not a trend.

Next checkpoint

Oct 9, 2026 — ZMR update; Oct 14, 8:30 ET — September CPI; Oct 27–28 — FOMC meeting

On X today

The 10-year U.S. Treasury yield was 5.31% on October 5, the highest of 2026 in the Treasury's daily series. Meanwhile the one-year rate fell over the week, from 4.59% to 4.47%. Long-term money is getting more expensive; one-year money is not. The curve steepened: the gap between 10 years and 3 months widened from 0.96 to 1.09 percentage points in a week. For a box, what matters is the part of the curve that matches its term. A one-year box is compared with one-year rates, not ten-year ones. Higher long-term yields matter more for mortgages and long-term loans. ZMR: 4.85% as of October 2 (363-day term). Next value after the October 9 close. Ahead on the calendar: September CPI on October 14, FOMC meeting on October 27–28. Sources: U.S. Treasury (curve as of Oct 5), New York Fed.

View on X

What term costs. U.S. Treasury curve on October 5: 1 month 4.05%, 3 months 4.22%, 6 months 4.30%, 1 year 4.47%. The overnight rate, EFFR, was 3.88% (October 2). The longer the term, the more expensive the money: locking in a rate for a year now costs more than borrowing overnight. A comparison on one date, October 2: EFFR 3.88%, one-year Treasuries 4.46%, ZMR (SPX box, 363 days) 4.85%. The conventions differ (overnight, coupon-equivalent yield, simple ACT/360), so the gaps are approximate. Floating margin rates follow short-term rates. A box locks in a rate for its term, and that rate includes the price of term. It is a payment for certainty, not a gain or loss known in advance: the outcome depends on how short-term rates move over that term. Over the week the one-year rate fell 0.12 percentage points (from 4.59% on September 28). ZMR update after the October 9 close. Sources: U.S. Treasury, New York Fed, Zero Margin (ZMR).