What Is 0DTE Gamma? How Gamma Squeezes Work on Expiration Day
Learn how dealer positioning and Gamma walls act as invisible magnets and trampolines for intraday 0DTE price action.
Quick Answer
0DTE Gamma describes how quickly an option’s delta (directional exposure) changes as the underlying price moves, specifically applied to options that expire on the same trading day. Because there is zero time remaining until expiration, 0DTE options possess hyper-concentrated Gamma, making their prices extremely sensitive to small movements in the underlying index or stock.
To consistently trade 0DTE options, retail traders must look beyond basic technical analysis and understand the structural plumbing of the market: Dealer Gamma Exposure (GEX).
The Role of the Market Maker
When you buy a 0DTE call option, you are usually buying it from a market maker (a dealer). The dealer’s job is not to bet against you; their job is to provide liquidity and collect the bid-ask spread.
To ensure they don’t lose money if the market skyrockets, the dealer must hedge the option they just sold you by buying the underlying asset (like SPX futures).
Gamma: The Rate of Change
As the market moves, the dealer’s risk profile changes instantly. Gamma measures how fast that risk changes.
Because 0DTE options have zero time left, their Gamma is hyper-concentrated. If the SPX moves 10 points toward a major strike price, the dealer’s required hedge changes drastically.
Positive vs. Negative Gamma Regimes
Positive Gamma (The Dampener)
When dealers are in a positive Gamma position (usually when the market is near all-time highs), their hedging algorithm forces them to buy when the market drops and sell when the market rises. This acts as a shock absorber, suppressing volatility and creating tight, slow-moving intraday ranges.
Negative Gamma (The Accelerator)
When the market drops significantly and puts are heavily in the money, dealers flip into negative Gamma. Now, their algorithm forces them to sell when the market drops (to hedge their short puts) and buy when the market rises. This acts as an accelerator, throwing gasoline on the fire and causing massive, violent intraday 0DTE swings.
By tracking where the largest open interest lies—often called “Gamma Walls”—traders can map out the exact levels where dealer hedging will either halt a rally or accelerate a crash.
Knowledge Path
Explore Related 0DTE Concepts
Realized vs. Implied Volatility: The Options Pricing Gap
Understand the critical difference between Implied Volatility (expectation) and Realized Volatility (actual movement) in 0DTE options.
Volatility Skew: Why Puts Cost More Than Calls
Discover why Implied Volatility is not uniform across all strike prices, and why out-of-the-money puts generally carry a higher premium than equivalent calls.
What Is IV Rank (IVR)? How to Measure Relative Volatility
Discover how IV Rank (IVR) and IV Percentile (IVP) help traders determine if current implied volatility is actually high or low relative to its own history.
What Is Implied Volatility (IV)? Understanding 0DTE Pricing
Understand Implied Volatility (IV), how it differs from realized volatility, and why it is the most critical factor in pricing 0DTE options.
Financial Risk Disclaimer
The content provided on 0DTEOptionsNews.com is strictly for informational and educational purposes. We provide structural market analysis and track macroeconomic news; we do not provide individualized investment advice. Trading zero-days-to-expiration options involves extreme risk, massive intraday volatility, and may lead to a total loss of capital. Market data may be delayed. Always verify information independently before executing a trade. Read our full Financial Disclaimer.