SPY gamma exposure: flip, call wall, put wall

Dealer gamma by strike for SPDR S&P 500 ETF, from the option chain itself: two books, the level where net gamma changes sign, and the two strikes that carry the most. Expiries out to 120 days.

data as of 2026-11-03 16:15:00 ET · not updating right now · replay SPY in the terminal
Spot
754.4
from put-call parity
Zero gamma flip
755.4
0.1% above spot
Call wall
760
0.7% above spot
Put wall
750
0.6% below spot
Net gamma, volume
-$658M
per 1% move
Net gamma, OI
-$12.22B
per 1% move
Price sits below the flip at 755.4: on this book dealer hedging adds to a move rather than leaning against it.
The session, 2026-11-03 priceflipcall wallput wall
760750755.4754.4 net gamma, volume book09:3010:3011:3012:3013:3014:3015:30
day11-0311-0210-3010-2910-2810-2710-2610-2310-2210-2110-2010-19 28 points · volume book · levels drawn as they stood
Strikes through the day levelchange since the open absorbs a movefeeds itprice
76576476376276176075975875775675575475375275175074974874774674574474309:3010:3011:3012:3013:3014:3015:30
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
769
768
767
766
765
764
763
762
761
760
call wall
759
758
757
756
755
754
spot
753
752
751
750
put wall
749
748
747
746
745
744
743
742
741
740
739
By expiry, volume book
expiryflipcallputnet
2026-11-04754.8760750-$160M
2026-11-05753.5745760+$43M
2026-11-06758770750-$312M
2026-11-09744.4757750+$99M
2026-11-10747765755+$47M
2026-11-11757.1775740-$8M
How far to trust this bookA

an index or a broad ETF with a tape that prints several times a second.

Prints a second, regular session15.69
Strikes where the two books agree on the sign84%
Contracts traded today, expiries shown2,179,454

What this page assumes

  • Calls count as dealer-long gamma and puts as dealer-short. That is a convention, not a measurement: open interest does not say who holds a contract.
  • The volume book signs today's traded contracts. The open-interest book uses positions as of the last close and does not move inside the day.
  • Spot is derived from the option quotes by put-call parity, so it can sit a few cents from the last trade in the underlying.
  • SPY options are American style and the underlying may pay a dividend. Each expiry is priced off its own forward from put-call parity, and gamma is Black-Scholes on that forward. Deep in-the-money contracts near a dividend are the weak spot.
  • Every figure is dollars of dealer delta per 1% move in SPY, the unit that compares across symbols.
  • There is no tape-signed book on this page. That book exists only where a live engine runs.

Questions

What does it mean that SPY is below its flip?

Net dealer gamma on this book is negative, so hedging flows tend to add to a move. It says nothing about direction.

Why are there two books?

Open interest is positioning as it stood at the last close. Volume is what traded today. When they disagree, that split is the reading.

Is this a trading signal?

No. We tested wall touches and flip crosses on SPX across more than a thousand sessions and found no edge that survives costs. These are measurements of where hedging concentrates.

How is this different from the SPX terminal?

SPX runs on a live engine: every second, with a third book signed print by print from the trade tape. This page is rebuilt from chain snapshots and carries the two conventional books only.