Market Structure Glossary
A professional dictionary linking options variables directly to workflows.
Gamma Exposure (GEX)
Net dollar exposure per 1% change in the underlying asset's price. Measures the aggregate hedging requirements of options dealers.
Net GEX
The cumulative Gamma Exposure aggregated across all strikes and expirations for a specific underlying asset, representing the net market maker positioning.
Gamma Flip
The spot price level where net dealer options exposure pivots from positive (long gamma) to negative (short gamma).
Dealer Hedging
The process by which options market makers buy or sell shares of the underlying stock to maintain delta-neutral books.
Delta Hedging
A risk management strategy that aims to neutralize the directional risk (delta) of a derivatives position by executing offsetting stock trades.
Call Wall
The strike price containing the highest concentration of call option open interest, acting as a ceiling for underlying spot price moves.
Put Wall
The strike price containing the highest concentration of put option open interest, acting as a floor for underlying spot price moves.
Vanna
A second-order option Greek that measures the sensitivity of Delta to changes in Implied Volatility (IV).
Charm
A second-order option Greek that measures the sensitivity of Delta to time decay (passage of time). Also known as delta decay.
Volatility Smile
The implied volatility curve across option strikes for a single expiration, showing higher IV for out-of-the-money options.
Volatility Skew
The difference in implied volatility between out-of-the-money puts and out-of-the-money calls for a specific expiration.
Volatility Term Structure
The curve displaying the implied volatility of options across different expiration cycles, showing expectations of volatility over time.
Volatility Risk Premium
The tendency for options implied volatility to exceed realized volatility, reflecting the premium paid by option buyers for portfolio protection.
Dealer Inventory
The net options inventory held by market makers, which dictates their dynamic delta and gamma rehedging requirements.
Liquidity Regime
The current liquidity environment, categorized by bid/ask spreads, order book depth, and market maker participation levels.
Order Flow
The stream of transactions executed on an exchange, analyzed to identify block trades and unusual options activity.
Market Maker
A financial institution that quotes both bid and ask prices in a stock or option, providing liquidity to facilitate continuous execution.
Open Interest
The total number of outstanding options contracts that have not been settled, expired, or closed.
Volume
The number of options contracts traded during the current trading session, indicating immediate liquidity interest.
Pinning Effects
The tendency for the underlying spot asset price to close exactly at a strike with high open interest on options expiration days.
Option Chain
A matrix layout displaying all available options contracts (calls and puts) for a specific underlying asset across strike prices and expiration dates.
0DTE Option
Zero-Days-to-Expiration options contracts that expire on the active trading day, generating extreme intraday Gamma sensitivity.
Volga (Vomit)
A second-order Greek measuring the rate of change of Vega with respect to changes in Implied Volatility (DvegaDvol).
Zomma
A third-order Greek measuring the sensitivity of Gamma to shifts in Implied Volatility (DgammaDvol).
Dark Pool Print
Off-exchange non-displayed institutional block trades executed without prior public order book display.
Intermarket Sweep Order (ISO)
An aggressive multi-venue execution algorithm designed to consume all liquidity across multiple exchanges simultaneously in milliseconds.
Kalman Filter Spread
A recursive Bayesian state-space algorithm that dynamically calculates time-varying hedge ratios for statistical arbitrage pair trading.
Pre-Market Order Matching
The un-crossed multilateral auction matching process (9:00 AM - 9:08 AM) that discovers the official Equilibrium Opening Price.
Kyle's Lambda (λ)
Microstructure price impact coefficient measuring the expected spot price shift per crore of net signed aggressive order flow.
Amihud Illiquidity Ratio
An econometric liquidity ratio measuring the absolute return response of an asset relative to its trading turnover volume.
Dollar Delta Exposure (DEX)
The aggregate currency value of directional delta exposure currently held by options market makers across active option strikes.
Dealer Stress Index
A normalized metric (0-100) assessing market maker inventory imbalance and hedging capacity relative to underlying market liquidity.
Confluence Matrix
A multi-model quantitative framework combining order flow, Greeks, breadth, and statistical models into an explainable four-pillar thesis.
Kelly Criterion
A mathematical formula for optimal capital allocation that maximizes long-term portfolio growth based on model winrate and risk-reward ratio.
Unusual Options Activity (UOA)
Algorithmic detection of anomalous options trades characterized by extreme volume-to-open-interest ratios (Vol/OI > 3.0x) and aggressive ask sweeps.
Structure of Arrays (SoA)
A high-performance memory layout organizing identical metric attributes contiguously in cache, enabling SIMD parallel vectorized calculations.
SNAP_QUOTE (Mode 3)
High-throughput binary WebSocket stream delivering full OHLCV, cumulative open interest, and Level-2 Best-5 market depth tick-by-tick.
Signal Invalidation Level
The deterministic price boundary where a quantitative model thesis becomes mathematically void, triggering automatic position closure.
Delta Flow Velocity
The rate of change in net institutional options delta buying or selling per minute, signaling impending directional breakout momentum.
Max Pain
The strike price at which the total financial loss across all expiring options contract buyers is maximized upon settlement.