Quick definition
An options Greek measuring the rate of change of Delta. High Gamma means your directional exposure changes rapidly with stock price movement.
Where gamma lives
Gamma is highest for at-the-money options near expiration. A 0DTE at-the-money straddle has terrifyingly high gamma — a few dollars of underlying movement can flip a position from delta-neutral to dangerously directional in minutes. Far OTM and deep ITM options carry near-zero gamma because their deltas are already pinned to 0 or |1|.
The short-gamma trap
Premium sellers are short gamma by construction. As long as the underlying stays inside the breakevens, time decay and convexity work for them. When price breaches the breakeven, delta runs against them faster than they can hedge — this is why credit strategies size positions conservatively and Treeova's Adaptive Risk Engine widens trails in high-IV regimes where realized gamma exposure spikes.
How Treeova uses it
Position-level gamma is one of the inputs Arch-AGI evaluates when scoring an exit decision. A high-gamma position near expiration with declining conviction is a strong candidate for an early close — the engine doesn't need a max-loss hit to take action when the structural risk is visible in the Greeks.