Reference
Options Trading Glossary
A plain-English glossary of options trading terms — dealer gamma, 0DTE, GEX, gamma flip, call wall, put wall, order flow and more, explained simply.
Plain-English definitions of the terms you'll see across BlackOut and the Learn hub. Each links to a deeper guide where one exists.
0DTE (Zero Days to Expiration) — An option that expires the same trading day. Carries large, fast-decaying gamma, making intraday dealer positioning critical. See 0DTE SPX Options Strategy.
Call Wall — The strike above current price with the largest concentration of call gamma; often acts as resistance or a magnet. See Call Wall & Put Wall.
Dealer — A market maker who takes the other side of your options trades and hedges continuously to stay neutral. Their hedging is what moves markets intraday.
Dealer Gamma Exposure — A measure of how much dealers must buy or sell as price moves. The foundation of positioning analysis. See What Is Dealer Gamma Exposure?.
Gamma — The rate of change of an option's delta as the underlying moves. High gamma means hedging needs change quickly.
Gamma Flip — The price where aggregate dealer gamma crosses from positive to negative — the line between a calm, pinning market and a fast, trending one. See Gamma Flip Explained.
Gamma Squeeze — A feedback loop where dealer hedging of short-gamma call positions forces them to chase price, amplifying a move. See Gamma Squeeze Explained.
GEX (Gamma Exposure) — Total dealer gamma aggregated across the options chain; positive stabilizes the market, negative amplifies it. See What Is GEX?.
Long Gamma — When dealers hedge against the move (sell rallies, buy dips), dampening volatility and pinning price.
Options Flow — The stream of options trades hitting the tape. Useful only with context — opening vs. closing, bid vs. ask, hedged vs. directional. See How to Read Options Flow.
Put Wall — The strike below current price with the largest concentration of put gamma; often acts as support. See Call Wall & Put Wall.
Short Gamma — When dealers hedge with the move (buy strength, sell weakness), amplifying volatility. The regime behind fast selloffs and squeezes.
SPX — Options on the S&P 500 index, cash-settled and European-style — the primary market for dealer-gamma and 0DTE trading.
Want the full picture? Start with the pillar guide: Dealer Gamma & Options Flow. Or see it all live →
BlackOut provides educational tools and market analysis only and does not provide investment advice. Options trading involves substantial risk and is not suitable for every investor.