Dealer Gamma & Options Flow: The Complete Guide

Most traders watch price. The desks watch what sits underneath price — dealer positioning. This guide is the map to that hidden layer: what dealer gamma is, why it moves the S&P 500 intraday, and how to read the levels the professionals actually trade around. It also serves as the hub for our deeper guides — each section links to a full breakdown.

Why dealer positioning moves the market

Every time you buy or sell an option, a market maker takes the other side. To stay neutral, they continuously hedge by buying and selling the underlying as price moves — a process called delta hedging (see Delta Hedging Explained and Market Maker Hedging Explained for the full mechanics). Multiply that hedging across every open contract in SPX and you get a force large enough to pin the market at some levels and accelerate it through others. Understanding that force is the single biggest edge available to a retail options trader — and it's the foundation everything at BlackOut is built on.

Consider a concrete example. SPX is trading at 5,500. There are tens of thousands of open call contracts clustered at the 5,550 strike. Every tick higher forces dealers to buy shares to hedge those calls, and those purchases push SPX higher still. The reverse happens on the way down with puts. That mechanical buying and selling is not opinion — it's math — and it happens on a scale that dwarfs most directional order flow.

The core concept: dealer gamma exposure

Gamma exposure measures how much dealers must buy or sell as price moves, and in which direction. When dealers are long gamma, they sell rallies and buy dips — dampening volatility and pinning price. When they're short gamma, they buy strength and sell weakness — amplifying every move. Knowing which regime you're in tells you whether to fade extremes or ride momentum. The Greek that drives all of this — gamma — and its relationship to delta, theta, and vega are covered in Options Greeks Explained. → Read the full breakdown: What Is Dealer Gamma Exposure?

The levels that matter

Three levels concentrate most of the hedging pressure:

The gamma flip is the price where dealers switch from long to short gamma — the line between a calm day and an explosive one. → Gamma Flip Explained

The call wall and put wall are large concentrations of gamma that often act as resistance and support. → Call Wall & Put Wall Explained

Aggregate all of it and you get GEX — total gamma exposure across the chain. → What Is GEX?

Reading order flow

Positioning tells you where the battle lines are; options order flow tells you who's showing up. Learning to separate real institutional signal from routine hedging is its own skill — and it extends beyond the lit tape into dark pool activity, where institutions trade size off-exchange before layering on options exposure. Spotting unusual options activity on top of that dark pool context is what turns raw flow into actionable signal. → How to Read Options Flow

Applying it to 0DTE

Zero-days-to-expiration options carry enormous, fast-decaying gamma, which makes intraday dealer positioning more important for 0DTE than for any other timeframe. That same gamma concentration is what makes premium-selling structures like the iron condor viable when the positioning read supports a range. Meanwhile, implied volatility determines how rich the premiums are on any given session — and whether the trade is worth taking at all. → 0DTE SPX Options Strategy Guide, Best 0DTE Trading Strategies, and Is 0DTE Gambling?

Where to go next

New to the terms? Start with the Options Trading Glossary. Curious how a sharp move happens? Read Gamma Squeeze Explained. Want to understand the Greeks underneath all of it? Options Greeks Explained covers delta, gamma, theta, and vega in plain English.

See it on the tools. Thermal maps the gamma flip, call wall, put wall, and GEX heatmap live every session. SPX Slayer is the 0DTE desk — graded setups, live tracking, public record. HELIX scans institutional flow for unusual activity so you see who's showing up. Night Hawk handles swing and overnight setups outside the 0DTE window. And Largo AI can walk you through any of it conversationally if you're just getting started. Get access →

BlackOut provides educational tools and market analysis only and does not provide investment advice. Options and equities trading involve substantial risk and are not suitable for every investor.