GEX API - Gamma Exposure API Endpoint | Real-Time Options Data - FlashAlpha
Lab API Gamma Exposure (GEX)

Gamma Exposure (GEX) API

Quantify dealer gamma exposure by strike to identify hedging pressure zones, support/resistance levels, and the gamma flip point.

New to gamma exposure? What Is GEX? covers the formula, dealer hedging mechanics, and how to read gamma flip levels. Also see: GEX Trading Guide for practical trading strategies using this data.

Endpoint

GET /v1/exposure/gex/{symbol}
Auth required (X-Api-Key) Rate Limited: Yes

Parameters

Name In Required Default Description
symbol path yes - Underlying symbol
expiration query no all Filter to single expiry (yyyy-MM-dd)
min_oi query no 0 Minimum open interest threshold
Note: Full-chain GEX (all expirations) requires the Growth plan. Add ?expiration=yyyy-MM-dd to filter by a single expiry on lower plans.
curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/exposure/gex/SPY"
import requests

resp = requests.get(
    "https://lab.flashalpha.com/v1/exposure/gex/SPY",
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = resp.json()
print(f"Net GEX: ${data['net_gex']:,.0f}")
print(f"Gamma Flip: {data['gamma_flip']}")
const resp = await fetch(
  "https://lab.flashalpha.com/v1/exposure/gex/SPY",
  { headers: { "X-Api-Key": "YOUR_API_KEY" } }
);
const data = await resp.json();
console.log(`Net GEX: $${data.net_gex.toLocaleString()}`);
console.log(`Gamma Flip: ${data.gamma_flip}`);

Response

{
  "symbol": "SPY",
  "underlying_price": 597.505,
  "as_of": "2026-02-28T16:30:45Z",
  "gamma_flip": 595.25,
  "net_gex": 2850000000,
  "net_gex_label": "positive",
  "strikes": [
    {
      "strike": 575.0,
      "call_gex": 12500000,
      "put_gex": 8900000,
      "net_gex": 21400000,
      "call_oi": 15000,
      "put_oi": 12000,
      "call_volume": 250,
      "put_volume": 180,
      "call_oi_change": 500,
      "put_oi_change": -200
    }
  ]
}

Key Response Fields

Field Type Description
symbolstringUnderlying symbol
underlying_pricenumberCurrent price of underlying
as_ofstringISO 8601 timestamp
gamma_flipnumberStrike where net GEX crosses zero — the gamma flip point
net_gexnumberAggregate net gamma exposure in dollars
net_gex_labelstringGamma regime label (positive or negative)
strikesarrayPer-strike breakdown
strikes[].strikenumberStrike price
strikes[].call_gexnumberCall gamma exposure at this strike
strikes[].put_gexnumberPut gamma exposure at this strike
strikes[].net_gexnumberNet (call + put) gamma exposure
strikes[].call_oinumberCall open interest
strikes[].put_oinumberPut open interest
strikes[].call_volumenumberCall volume
strikes[].put_volumenumberPut volume
strikes[].call_oi_changenumberDay-over-day call open interest change
strikes[].put_oi_changenumberDay-over-day put open interest change

Errors

Status Description
400Invalid expiration format
403Full-chain GEX requires Growth plan
404Symbol not found or no data

Plans & Rate Limits

Plan Rate Limit Access
Free5 requests/dayStock quotes, GEX & key levels (single expiry), tickers, options meta, symbols, surface - individual US equities only
Basic100 requests/dayEverything in Free + ETFs & index symbols (SPY, QQQ, SPX, VIX...) + DEX/VEX/CHEX exposure + max pain + Market Overview
Growth2,500 requests/day+ Summary, narrative, history, option quotes, full-chain GEX (no expiry filter)
AlphaUnlimitedFull access + advanced volatility analytics

What Is Gamma Exposure?

Gamma exposure (GEX) measures the dollar amount of shares that options dealers must buy or sell to delta-hedge for every 1% move in the underlying price. When dealers are long gamma (positive GEX), they buy dips and sell rallies - dampening volatility and creating mean-reverting, range-bound markets. When dealers are short gamma (negative GEX), their hedging amplifies moves - leading to trending, volatile price action. The gamma flip point marks where net exposure switches sign, often acting as a key pivot level.

Common Use Cases

  • Identify the gamma flip point - the strike where dealers switch from long to short gamma, often a major pivot level
  • Find support/resistance zones - strikes with high positive GEX act as magnets that absorb price moves
  • Gauge market regime - positive net GEX means mean-reverting; negative net GEX means trending/volatile
  • Detect pinning risk - high GEX concentration at a strike near expiry can pin the underlying price
  • Size positions - use the magnitude of GEX to calibrate expected volatility and set stop distances

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