SPY calls expiring that date in the strikes we track traded 1.7x their open interest, by 09:42 ET on Oct 21, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
CStrike6.1x
Expiry1.7x
Evidence
The numbers behind this snapshot, Oct 21, 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
6.1x
Volume / prior open interest, the expiry's tracked strikes
1.7x
Days to expiry
0
Why it fired
Rule
volume/prior OI >= 5.0 and >= 3.0 x this expiry's call volume/OI; prior OI >= 1000; volume >= 2000
Values that cleared it
Expiry ratio: 1.71; Ratio: 6.14
Contracts traded behind each figure
Expiry calls: 40
Baseline
this expiry's call volume/open interest, same session: 1.71
Baseline window
same expiry, same session (n = strikes with open interest)
The median is SPY's put/call volume ratio for contracts 1 to 3 weeks out over the last 9 sessions. 59,078 put and 5,695 call contracts by 09:47 ET on Oct 21, 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 9 sessions. 4,208 call and 2,115 put contracts by 09:42 ET on Oct 21, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
The median is SPY's put/call volume ratio for contracts within a week over the last 9 sessions. 3,084 put and 621 call contracts by 09:32 ET on Oct 21, 2026. Tracked: up to 40 strikes around the money across 33 expirations.
The median is SPY's put/call volume ratio for contracts within a week over the last 9 sessions. 2,039 put and 764 call contracts by 09:32 ET on Oct 21, 2026. Tracked: up to 40 strikes around the money across 33 expirations.