HOOD gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Robinhood Markets, 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 45 days.

data as of 2026-09-18 16:00:02 ET · not updating right now
Spot
119.7
from put-call parity
Zero gamma flip
n/a
outside the range
Call wall
120
0.3% above spot
Put wall
105
12.3% below spot
Net gamma, volume
+$51M
per 1% move
Net gamma, OI
+$30M
per 1% move
No zero-gamma level inside the searched range: net gamma stays positive across it.
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
call wall · spot
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
put wall
By expiry, volume book
expiryflipcallputnet
2026-09-25102.4120110+$38M
2026-10-02n/a120106+$5M
2026-10-09n/a127109+$1M
2026-10-16n/a120105+$6M
2026-10-23107.9130105+$361K
2026-10-30n/a130105+$559K
How far to trust this bookD

a single stock with a thin tape; read the shape, not the sign.

Prints a second, regular session2.92
Strikes where the two books agree on the sign78%
Contracts traded today, expiries shown305,071

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.
  • HOOD 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 HOOD, 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 HOOD is above its flip?

Net dealer gamma on this book is positive, so hedging flows tend to lean against 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.