Dealer Gamma Positioning (Long vs. Short Gamma)
Dealer gamma positioning describes whether option market-makers are net long or net short gamma. Long-gamma dealers hedge against the move (buy dips, sell rips), which dampens volatility; short-gamma dealers hedge with the move (sell dips, buy rips), which amplifies it.
When customers buy more options than they sell at a given set of strikes, dealers are net short those options and therefore short gamma; when customers are net sellers, dealers are long gamma. Because dealers continuously re-hedge to stay delta-neutral, their gamma sign determines the direction of their hedging flow relative to the market.
A long-gamma (positive) book is a stabiliser: dealer hedging leans against price, so ranges compress and headlines get absorbed. A short-gamma (negative) book is an accelerant: dealer hedging leans with price, so a small push can cascade. The transition between the two regimes is often more important than the level of any single day.
This positioning is inferred, not observed directly - it is a proprietary estimate built from options-chain data. It is most reliable as a regime signal (are dealers stabilising or amplifying?) rather than a precise quantity.
Frequently asked
If dealers are short gamma, does it dampen or enhance market moves?
It enhances them. Short-gamma dealers hedge in the same direction as price - selling into declines and buying into rallies - which mechanically amplifies the move and widens the trading range.
Can you explain dealer gamma as simply as possible?
Dealers who sold you options must trade the underlying to stay neutral. When they are long gamma they lean against price and calm it; when they are short gamma they chase price and speed it up. That lean is dealer gamma.
How do you know which way dealers are positioned?
It is estimated from the open-interest mix across strikes and assumptions about which side dealers hold. It is read directionally - net long vs net short and where the sign flips - not as an exact figure.
Related terms
This term is part of a bigger picture: Gamma Exposure, Explained — the complete guide →