Dealer Gamma
Dealer gamma is the total gamma options dealers are estimated to carry across a symbol's options chain — the position that obliges them to buy or sell the underlying as its price moves, and whose hedging flow either pushes back against a move or feeds it.
What it is
Gamma is the rate at which an option's delta changes as the underlying moves. Whoever holds an option holds its gamma, and in listed options the other side of most customer trades is a dealer or market maker. Add up the gamma of every contract a symbol's dealers are estimated to hold — signed by the standard convention, weighted by open interest — and you have dealer gamma: a single position with a mechanical consequence. To stay hedged, its owner must trade the underlying against it, continuously, in size set by the position itself.
The direction of that forced trading depends on the sign. When dealers are long gamma in aggregate, hedging is countercyclical: rallies oblige them to sell, dips oblige them to buy, and the flow dampens volatility. When dealers are short gamma, hedging is procyclical: they buy rallies and sell dips, and the flow amplifies whatever started moving. Gamma exposure (GEX) is this same position expressed in dollars, strike by strike — the map on which the flip and the walls are features.
One honest caveat defines the whole subject: nobody outside a dealer's own risk system can see the actual position. Dealer gamma is an estimate, inferred from public open interest under a stated assumption about which side customers took — conventionally, that customers in aggregate sell calls and buy puts, leaving dealers long call gamma and short put gamma. When real flow inverts that pattern, the estimate can be wrong in sign, which is why the assumption is published rather than buried.
How traders use it
- The regime read under every other levelThe flip, the walls, and the squeeze are all readings of the dealer gamma position. Traders who track one number track this: net dealer gamma near spot, and its sign, is the fastest summary of whether hedging will absorb or amplify the day's moves.
- Explaining pinning and air pocketsPrice pinning to a strike into expiration is long dealer gamma at work — hedging keeps pulling price back. The sudden air pocket through a level with no news is the short-gamma side: hedging chased the break instead of catching it. Dealer gamma is the mechanism behind both pictures.
- Sizing expectations, not entriesLarge dealer gamma near spot means a move will meet real mechanical flow; small dealer gamma means the options market will mostly watch. That calibrates how much follow-through to expect from a breakout or a breakdown before it happens.
What it is not
- It is not a data feed. There is no tape of dealer positions to subscribe to; every dealer gamma figure in existence is a model output, and the honest ones publish their convention.
- It is not directional. Long dealer gamma is not bullish and short dealer gamma is not bearish — long gamma dampens rallies exactly as much as it dampens selloffs, and short gamma amplifies both. It describes reaction, not direction.
- It is not the whole market. Dealer gamma measures one forced flow among many — earnings repricing, macro flows, and liquidations run through it regularly. It is the terrain, not the weather.
On SPY, in practice
SPY's dealer gamma is, in aggregate, close to the US equity market's shock absorber setting. On mornings when SPY's net dealer gamma is large and positive, the index absorbs headlines that would move it twice as far on a short-gamma morning — same news, different terrain. Tracking the sign and size of that position is most of what 'reading the gamma regime' means in practice.
SPY's current dealer gamma terrain — flip, walls, and the per-strike map, from the settled base stamped on the page — is on the SPY gamma page.
Frequently asked questions
Can anyone see dealers' actual gamma positions?
No. Dealer books are private. Every published dealer gamma figure — Profit Builders' included — is an estimate inferred from public open interest under a sign convention that stands in for which side customers took. Vendors differ in their conventions and windows, which is why their numbers differ; the reputable ones state the assumption, as Profit Builders does on its gamma exposure methodology page.
What is the difference between dealer gamma and GEX?
Dealer gamma is the position; GEX (gamma exposure) is that position measured in dollars and located by strike. GEX takes each contract's gamma, weights it by open interest and the spot price squared, and sums it — producing the per-strike map from which the gamma flip, call wall, and put wall are read.
Is long dealer gamma bullish?
No. Long dealer gamma means hedging dampens movement in both directions — rallies get sold into, selloffs get bought. Short dealer gamma means hedging amplifies movement in both directions. Neither sign contains a directional view; they describe how the market will respond to a move, not which move is coming.
Why does dealer gamma matter more around expirations?
Gamma concentrates as expiration approaches and near the money, so the hedging obligation per contract peaks in the final days — and same-day (0DTE) contracts now carry a large share of index volume. The result is that intraday hedging flows are larger relative to ordinary volume than they were a decade ago, and the levels they defend are increasingly intraday phenomena rather than monthly ones.
How these levels are calculated, with the model's stated limits: the gamma exposure methodology · Today's levels for all 194 symbols: the GEX hub.
Profit Builders provides market-data analysis and educational information, not investment advice. Options trading involves substantial risk. Past performance does not guarantee future results.