Options Flow Glossary A–Z

Full glossary definitions

0DTE (zero days to expiration)

0DTE options expire the same trading day. Gamma and theta move fastest near the money on that clock.

Aggressor side (bid / ask)

Aggressor side estimates who crossed the spread: prints at or above the ask often look like aggressive buying; at or below the bid, aggressive selling. Mid is ambiguous.

Call wall

A call wall is the strike above spot with the densest call open interest or call-side gamma. Traders often treat it as resistance when dealers hedge.

Dealer hedging

Dealer hedging is market makers buying or selling the underlying to stay near delta-neutral as price and gamma change.

Delta exposure (DEX)

DEX estimates share-equivalent directional weight of an options trade, roughly delta × size (with the usual multiplier).

Delta impact (DEI)

DEI scales delta exposure by typical stock volume so the same DEX reads louder in a quiet name than in a hyper-liquid one.

Gamma exposure (GEX)

GEX estimates aggregate dealer gamma from listed options. Positive gamma tends to dampen moves; negative gamma tends to amplify them. Option gamma is the building block; a gamma squeeze is a feedback loop when short-gamma hedges chase price higher.

IV crush

IV crush is a sharp drop in implied volatility after uncertainty resolves, often after earnings. Premium can fall even when the stock moves your way.

IV Rank

IV Rank places today’s implied volatility between its recent high and low so “expensive” or “cheap” is relative to that underlying’s history.

Max pain

Max pain is the underlying price that theoretically minimizes total option-holder payoff at expiration.

Moneyness (ITM / ATM / OTM)

Moneyness labels a contract relative to spot: in-the-money (ITM), at-the-money (ATM), or out-of-the-money (OTM).

Open interest (OI)

Open interest is how many options contracts remain open. Unlike volume, it does not reset each morning and usually updates after the session.

Option flow

Option flow is the time-and-sales stream of options prints: contract, size, premium, and inferred aggressor side.

Options block trade

An options block is a large single print, or same-second aggregate, sized well above typical retail clips.

Options sweep

A sweep is a large order filled across multiple exchanges in rapid succession, usually to grab available liquidity quickly.

Pin risk

Pin risk is expiration uncertainty when spot sits near a strike with large open interest: assignment and last-minute hedging get noisy.

Put wall

A put wall is the strike below spot with the densest put open interest or put-side gamma. Traders often treat it as support when dealers hedge.

Put/call ratio

Put/call ratio compares put activity to call activity by contracts, volume, or premium. Context decides whether heavy puts mean hedges or bearish bets.

Smart money flow

In scanners, “smart money” usually means large or institutional-style prints. It is a size heuristic, not account identity.

Unusual options activity (UOA)

UOA flags contracts or underlyings trading far above recent norms in volume, size, or premium. It is an attention screen, not a directional signal.

Volume / open interest (Vol/OI)

Vol/OI is today’s volume divided by open interest. High ratios mean today’s trading is large versus the standing book.