SPX · PUTS · OCT 19Settled
Open interest in SPX puts expiring Oct 19 rose 227,184 at the Oct 16 settlement
As of . Source: Cboe settlement open interest archive.
On the page at squawkflow.com/options-flow/2026-10-16/spx-puts-oct-19-2026-open-interest-change: the evidence table and the rule this settlement figure passed; and up to six other SPX snapshots from Oct 16, 2026.
102,163 to 329,347 contracts between the Oct 15 and Oct 16 settlements, 222% of the prior figure.
Before102,163
After329,347
Evidence
The numbers behind this snapshot, Oct 16, 2026 settlement. Open interest change, not trades; it does not say which side opened or closed.| Measure | Value |
|---|
| Open interest, earlier settlement | 102,163 |
|---|
| Open interest, later settlement | 329,347 |
|---|
| Change (contracts) | +227,184 |
|---|
| Change as a share of the earlier figure | 222% |
|---|
| Earlier settlement | Oct 15, 2026 |
|---|
| Later settlement | Oct 16, 2026 |
|---|
| Days to expiry | 3 |
|---|
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: 227,184; Change as a share of the earlier figure: 2.2237
- Contracts traded behind each figure
- Open interest changed: 194
- Baseline
- median absolute open interest change share, contracts within a week: 0.1969
- 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.
SPXCOCT 19Open interest change
57,810 to 140,321 contracts between the Oct 15 and Oct 16 settlements, 143% of the prior figure.