GEX Glossary

What Is Gamma Exposure (GEX)?

Gamma exposure (GEX) measures how much options dealers need to buy or sell in the underlying stock or index to stay hedged as its price moves, based on the gamma of their aggregate options positions.

What Is Net Gamma?

Net gamma is call gamma minus put gamma summed across an options chain — a single number showing which direction dealers are net hedging in, and whether that hedging is likely to dampen or amplify price moves.

What Is Spot Price?

Spot price is the current market price of the underlying asset — for SPX, the live index value; for ES, the live futures price — and it's the reference point every gamma exposure level is measured against.

What Is Dealer Hedging?

Dealer hedging is the process by which options market makers offset the risk of the options they've sold by trading the underlying itself, and it's the actual mechanism that turns options positioning into real, observable price flow.

Open Interest vs. Gamma Exposure: What's the Difference?

Open interest is a raw, static count of outstanding options contracts at a strike, while gamma exposure weights that same open interest by gamma and price to estimate the actual hedging flow it's likely to produce.

IV vs. HV vs. VIX: What's the Difference?

Implied volatility (IV) is the market's forward-looking estimate of future price movement priced into an option today, historical volatility (HV) is a backward-looking measure of how much the underlying actually moved in the past, and the VIX is a specific, standardized index that aggregates SPX options' IV into one real-time number.

What Is the IV/HV Ratio?

The IV/HV ratio divides an underlying's current implied volatility by its recent historical (realized) volatility, showing at a glance whether options are pricing in more future movement than the underlying has actually been making, or less.

What Is Implied Move (Expected Move)?

Implied move (also called expected move) is the options market's own built-in estimate of how far an underlying could move, up or down, by a given date — derived directly from at-the-money option prices, not a forecast or a guarantee.

What Is a Call Wall?

A call wall is the options strike with the largest concentration of call-side gamma exposure in an underlying's options chain, and it tends to act as resistance because dealers must sell the underlying as price rises toward it to stay hedged.

What Is a Put Wall?

A put wall is the options strike with the largest concentration of put-side gamma exposure, and it tends to act as support because dealers must buy the underlying as price falls toward it to stay hedged.

What Is the Gamma Flip Level (Zero Gamma)?

The gamma flip level — also called the zero gamma level — is the underlying price where aggregate dealer gamma exposure crosses from positive to negative or back, marking a shift between two different volatility regimes.

What Is Max Pain in Options Trading?

Max pain is the strike price at which the largest total dollar value of outstanding options — calls and puts combined — would expire worthless, a theory some traders use to guess where price might gravitate into expiration.

Positive vs. Negative Gamma Regime, Explained

A positive gamma regime is when dealers are net long gamma and their hedging tends to dampen volatility; a negative gamma regime is when dealers are net short gamma and their hedging tends to amplify it.

What Is a Gamma Squeeze?

A gamma squeeze is a rapid, self-reinforcing price rally driven by dealers who are forced to buy the underlying as heavy call buying pushes their short-call hedges further in-the-money.

What Are Vanna and Charm?

Vanna and charm are second-order options Greeks — vanna measures how an option's delta changes as implied volatility changes, and charm measures how delta changes purely with the passage of time.

0DTE Options and Gamma Exposure, Explained

0DTE (zero days to expiration) options are contracts expiring the same trading day, and because their gamma is extremely concentrated near the current price, they can produce outsized dealer hedging flow relative to their size.

What Is VIX Term Structure?

Volatility term structure — commonly called VIX term structure when applied to the S&P 500 — is the relationship between implied volatility and time to expiration across an underlying's different expiration dates, and whether it slopes up (contango) or down (backwardation) signals whether the market is pricing near-term or longer-term uncertainty more richly.

What Is Options Skew (Volatility Skew)?

Options skew is the difference in implied volatility across strike prices at the same expiration, and on equity indices like SPX it typically shows up as out-of-the-money puts pricing in more implied volatility than equidistant out-of-the-money calls, reflecting persistent demand for downside protection.

How to Read the VIX as a Market Signal

Reading the VIX as a market signal means looking past whether it went up or down and at its actual level, its trend, and its relationship to longer-dated volatility, since the same VIX print can mean very different things depending on that context.

What Is Wall Strength Scoring?

Wall strength scoring is a plain-English way of rating how significant a gamma level actually is — GammaWalls labels every call wall and put wall Fragile, Moderate, Strong, or Dominant instead of leaving you to eyeball a raw GEX number.

What Is Wall Migration (Wall Shift)?

Wall migration is the tracked movement of a call wall or put wall from one intraday scan to the next — GammaWalls tags every wall unchanged, moved up, or moved down against its prior read, so a shift is visible the moment it happens.

What Is GEX Imbalance?

GEX imbalance is the ratio of call-side to put-side gamma exposure in dollar terms, showing at a glance which side of the options chain currently dominates dealer positioning.

What Is Directional Bias in Gamma Analysis?

Directional bias is a structural read — bullish, bearish, or neutral — derived from the overall gamma picture, paired with a confidence score reflecting how clearly the underlying data supports that read.