After CPI, the curve moved; broker rates did not: what changes in borrowing costs?
- Applies to:
- SPX box spread, American-style box spread, Half box
- Risk type:
- Financing cost
Fact
September CPI (BLS, October 14, 8:30 ET): +0.6% m/m, +3.7% y/y; core +0.3%/+2.6%. Treasury curve on October 14: 1M 4.11% (+1 bp), 3M 4.28% (+2), 1Y 4.53% (+5), 2Y 4.82% (+3), 10Y 5.19% (−2). SOFR 3.89%, EFFR 3.88% (October 13); Fed target range 3.75–4.00%. Margin on $100k (broker pages dated October 3): IBKR 5.38%, Schwab 10.575%, Robinhood 4.75%, E*TRADE 11.2%; average 7.98%. ZMR 5.11% (October 13, 01:01 ET, 367 days), 2.86 pp below the average.
Sources: BLS CPI (September CPI, released October 14, 2026, 8:30 ET); U.S. Treasury, Daily Treasury Par Yield Curve Rates (curve as of October 14, 2026); Federal Reserve Bank of New York, reference rates (SOFR and EFFR as of October 13, 2026); broker rates — pages of IBKR, Schwab, Robinhood, E*TRADE (as of October 3, 2026); ZMR — Zero Margin calculation.
Our reading
The short and intermediate parts rose by +1 to +5 bp; the 10Y fell by 2 bp. Broker rates have not been updated since October 3; ZMR is dated October 13. September PPI was released today at 8:30 ET (final demand): +1.3% m/m, +6.3% y/y — the highest since March 2022 m/m and December 2022 y/y; it is not included in the October 14 curve. Next dates: October 16 monthly options expiration; October 27–28 FOMC.
What to check
- Current margin rates on broker pages.
- The Treasury curve after PPI.
- SOFR/EFFR for October 14.
Limits
Broker rates are from their pages as of October 3 and for a $100,000 balance. ZMR was observed October 13, 01:01 ET. This entry is not individual advice.
Next checkpoint
October 16 — standard monthly options expiration; October 27–28 — FOMC meeting
Read more
On X today
After September CPI (+0.6% / +3.7%), the October 14 curve: 1M 4.11% (+1), 1Y 4.53% (+5), 10Y 5.19% (−2). SOFR 3.89% / EFFR 3.88% (October 13). Broker margin rates are from pages dated October 3; average 7.98%. ZMR 5.11% (−2.86 pp). September PPI was released today: +1.3% m/m / +6.3% y/y.
Four published margin rates on $100k, from broker pages dated October 3: Robinhood 4.75%, IBKR 5.38%, Schwab 10.575%, E*TRADE 11.2%; average 7.98%. ZMR is 5.11% per year (observed October 13, 01:01 ET, 367-day term), 2.86 pp below that average. Meanwhile, the Treasury curve on October 14 differed from October 13 (1Y +5 bp, 10Y −2 bp). This series describes published rates and does not give advice; decisions are the reader's. Sources: IBKR, Schwab, Robinhood, and E*TRADE pages; U.S. Treasury; ZMR — Zero Margin calculation. More: zeromargin.loans/research/broker-margin-vs-sbloc-vs-box-spread
The feed describes market events and does not assess any specific account or position. Decisions are yours.