SPX · PUTS · DEC 4Settled
Open interest in SPX puts expiring Dec 4 rose 120,086 at the Oct 20 settlement
As of . Source: Cboe settlement open interest archive.
On the page at squawkflow.com/options-flow/2026-10-20/spx-puts-dec-4-2026-open-interest-change: the evidence table and the rule this settlement figure passed.
18,814 to 138,900 contracts between the Oct 19 and Oct 20 settlements, 638% of the prior figure.
Evidence
| Measure | Value |
|---|---|
| Open interest, earlier settlement | 18,814 |
| Open interest, later settlement | 138,900 |
| Change (contracts) | +120,086 |
| Change as a share of the earlier figure | 638% |
| Earlier settlement | Oct 19, 2026 |
| Later settlement | Oct 20, 2026 |
| Days to expiry | 45 |
Why it fired
- Rule
- |change| >= 10000 or (>= 2000 and >= 50% of prior), and |change share| >= 2.0 x bucket median; prior OI >= 1000
- Values that cleared it
- Change: 120,086; Change as a share of the earlier figure: 6.3828
- Contracts traded behind each figure
- Open interest changed: 58
- Baseline
- median absolute open interest change share, contracts 1 to 3 months out: 0.0503
- Baseline window
- last 20 sessions
- Baseline n
- 20
- Claim level
- 0, a reported fact
What happened next
This snapshot is itself a settlement figure, so it has no follow-up of its own.