Core Concepts — Ohey Documentation

Gamma Exposure (GEX)

Gamma Exposure quantifies the dollar amount of shares that options market makers must buy or sell to maintain delta neutrality as the underlying moves $1. It is the single most important concept on the Ohey platform.

Concept	What It Means	Market Impact
Positive GEX	Dealers are long gamma — they own options with convex payoffs	Dealers buy dips, sell rallies → stabilizing, mean-reverting price action
Negative GEX	Dealers are short gamma — they sold options and are exposed to moves	Dealers sell into selloffs, buy into rallies → amplifying, trending price action
Gamma Flip	The strike price where aggregate dealer gamma switches sign	Crossing the flip level often triggers a volatility regime change
Gamma Wall	A strike with extremely concentrated gamma exposure	Acts as a price magnet or barrier — dealers hedge heavily around it

Windows that use GEX: Gammatrix, Gamma Flip Zone, Gamma Exposure (GEX), GammaPulse, FlipTrack, Dealer Hedging Pressure, PulseDeck

Implied Volatility Surface

The IV surface maps implied volatility across two dimensions: strike price and time to expiration. It captures the market's consensus expectation for future realized volatility at every strike–expiry combination.

Volatility Smile / Skew: IV typically increases for deep out-of-the-money puts (crash protection premium) and sometimes for far OTM calls. The shape reveals supply/demand imbalances in the options market.
Term Structure: How IV changes across expirations. An inverted term structure (short-dated IV > long-dated) often signals event risk or near-term stress.
Surface Dynamics: Shifts in the IV surface between snapshots reveal how market expectations are evolving — critical for vol trading and hedging decisions.

Windows that use IV: IV Skew, VolCube, IV Surface, SkewSentinel, Vol Entropy

Open Interest Analysis

Open Interest (OI) is the number of outstanding options contracts at a given strike and expiration. Unlike volume (which measures contracts traded today), OI reflects accumulated positioning.

Delta-Weighted OI: Each strike's OI multiplied by its delta gives a directional reading. Heavy put-delta OI below the market suggests dealers have significant short delta exposure to hedge.
OI Clustering: Strikes with abnormally high OI often act as magnets for price (pinning) or support/resistance levels. Institutional positioning concentrates at round strikes.
Pin Risk: Near expiration, large OI at a strike creates incentive for market makers to push the underlying toward that strike to minimize payout.

Windows that use OI: Delta-Weighted OI, Flashback DWOI, OI Clustering Heatmap, Option Chains, PinMap, FlowRate

The Greeks

Options Greeks measure the sensitivity of an option's price to changes in underlying parameters. Understanding Greeks is essential for risk management and position sizing.

Greek	Measures	Practical Meaning
Delta (Δ)	Price change per $1 move in underlying	A delta of 0.50 means the option moves ~$0.50 for each $1 move. Also approximates probability of expiring ITM.
Gamma (Γ)	Rate of change of delta	High gamma = delta changes rapidly. Near-expiry ATM options have the highest gamma — small price moves cause large delta shifts.
Theta (Θ)	Time decay per day	How much value an option loses each day if nothing else changes. Accelerates as expiration approaches.
Vega (ν)	Sensitivity to implied volatility	Dollar change per 1% change in IV. Longer-dated options have more vega. Key for vol trading strategies.
Rho (ρ)	Sensitivity to interest rates	Usually minor for short-dated options. Becomes material for LEAPS and in changing interest rate environments.

Windows that focus on Greeks: Theta Decay, Vega Concentration, ThetaForge, EigenHedge, Dealer Hedging Pressure

Dealer Hedging Mechanics

When a retail trader buys a call option, a dealer (market maker) sells it. The dealer is now short delta and must hedge by buying the underlying stock. As the stock price moves, the dealer's delta exposure changes — forcing continuous rebalancing.

Hedging Pressure = |Gamma × Delta| × OI × 100: This formula (used in the Dealer Hedging Pressure window) quantifies the dollar amount of shares dealers must trade to stay hedged at each strike.
Net effect on markets: Dealer hedging flows are one of the largest, most predictable, non-discretionary forces in equity markets. Understanding them gives you a structural edge.
Intraday patterns: Dealer hedging accelerates near the close and especially on OPEX days (options expiration), when gamma effects are maximized.

Market Regime Detection

A market regime is a persistent state characterized by specific statistical properties — trending vs. mean-reverting, low-vol vs. high-vol, correlated vs. dispersed. Strategies that work in one regime often fail in another.

Regime	Characteristics	Typical Strategy Fit
Trending	Sustained directional moves; negative dealer gamma amplifies momentum	Directional spreads (Bull Call Spread, Bear Put Spread), trend-following entries
Mean-Reverting	Price oscillates around gamma walls; positive dealer gamma stabilizes	Iron condors, iron butterflies, premium-selling strategies near key strikes
Low Volatility	Compressed IV, narrow ranges, low option premiums	Long gamma via cheap straddles; position for eventual vol expansion
High Volatility	Elevated IV, wide daily ranges, expensive premiums	Premium selling at elevated IV, hedged short vol, calendar spreads
Crisis	Extreme put skew, correlation spike, dealer gamma deeply negative	Protective positions; avoid premium selling; monitor for reversal signals

Regime shifts: Transitions between regimes create the largest opportunities (and risks). The RegimeShift window monitors transition probabilities in real time using confidence ratios derived from the options positioning data.
Strategy alignment: PulseDeck uses regime detection to present regime-appropriate strategy considerations — e.g. Long Call or Bull Call Spread in bullish regimes vs. Iron Condor in neutral regimes. See methodology →

Platform Data Architecture

Every analytics window on Ohey is powered by a unified Data Abstraction Layer that aggregates, normalizes, and delivers options data in two modes:

HTTP

On-demand polling — request data when you need it. Supports optional auto-refresh at configurable intervals.

WebSocket

Real-time streaming — continuous live updates as market data changes. Available on PRO-tier windows.

Many PRO-tier windows offer both HTTP and WebSocket versions. The WebSocket version provides lower latency and continuous updates without manual refresh. All data is authenticated via JWT and encrypted in transit. For a deeper technical overview, see Data Infrastructure.