SPY puts expiring that date in the strikes we track traded 1.0x their open interest, by 09:42 ET on Oct 20, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
PStrike5.3x
Expiry1.0x
Evidence
The numbers behind this snapshot, Oct 20, 2026, 09:42 ET. Session volume from delayed options chain snapshots, published at least 15 minutes after capture. Totals cover the strikes captured around the money, not every listed strike. Not individual trades. Premium is an estimate: volume times the quote midpoint.
Measure
Value
Volume / prior open interest, this strike
5.3x
Volume / prior open interest, the expiry's tracked strikes
1.0x
Days to expiry
0
Why it fired
Rule
volume/prior OI >= 5.0 and >= 3.0 x this expiry's put volume/OI; prior OI >= 1000; volume >= 2000
Values that cleared it
Expiry ratio: 1.02; Ratio: 5.32
Contracts traded behind each figure
Expiry puts: 36
Baseline
this expiry's put volume/open interest, same session: 1.02
Baseline window
same expiry, same session (n = strikes with open interest)
The median is SPY's call/put volume ratio for contracts within a week over the last 8 sessions. 63,070 call and 38,687 put contracts by 10:27 ET on Oct 20, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
The median is SPY's call/put volume ratio for contracts within a week over the last 8 sessions. 23,257 call and 15,293 put contracts by 10:12 ET on Oct 20, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
The median is SPY's call/put volume ratio for contracts 1 to 3 weeks out over the last 8 sessions. 6,213 call and 3,226 put contracts by 09:47 ET on Oct 20, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
The median is SPY's call/put volume ratio for contracts within a week over the last 8 sessions. 2,490 call and 1,413 put contracts by 09:37 ET on Oct 20, 2026. Tracked: up to 40 strikes around the money across 33 expirations.