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Which way does estimated dealer hedging lean?

Send one US stock or ETF symbol. The Gamma Exposure API returns estimated net and gross GEX, the current gamma regime, the zero gamma level and the strikes carrying the most estimated exposure — dated, structured and ready for a person, script or AI agent.

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Input NVDA One liquid US stock or ETF
Estimate Quotes + OI + Black–Scholes Assumptions stay attached to the result
Output regime · flip · strikes One JSON object, with expiration detail

This is the commercial JSON product. The GEX directory remains free: nightly HTML snapshots for a curated ticker set, no email or key. Use the API when you need another supported symbol, machine-readable output, strike-level detail or an unattended workflow. The free key exercises the same API; paid access is for sustained, batch or unattended use.

Read the output in this order

  1. 01

    Start with regime and ratio

    regime gives the sign of net GEX. ratio is net divided by gross, so it shows whether the estimate is strongly one-sided or nearly balanced without depending on the ticker’s absolute scale.

  2. 02

    Then check flip and flip_status

    The flip is the zero crossing nearest spot on a grid from 0.9× to 1.1× spot. A null flip is meaningful when the status says no_sign_change_within_10pct; do not replace it with a guessed level.

  3. 03

    Inspect concentration and expiration

    heaviest_strikes ranks the five largest absolute GEX estimates. by_expiration shows how the net and absolute exposure is distributed through the option calendar instead of assuming the nearest expiry dominates.

  4. 04

    Keep the method and date beside the number

    as_of, method, note and disclaimer make the estimate auditable. stale: true tells you when an upstream outage caused the last stored snapshot to be served.

The endpoint

Base URL https://api.quantdata.uk. Send X-API-Key: qd_...; there is no SDK, OAuth flow or session state. The same key opens the Brooks Events API, Weis / Wyckoff API and Max Pain API. One plan covers all four.

Input Where Default What it changes
symbol path required US-listed stock or ETF with a liquid option chain and usable quotes.
by_strike query false Adds gamma.by_strike within 15% of spot, sorted by strike.

GET /v1/gamma/{symbol}

This is the recorded 200 response published in the API contract for NVDA. The heaviest-strike and expiration arrays are shortened here to keep the shape readable. 

$ curl -H "X-API-Key: qd_9f3c..." \
       https://api.quantdata.uk/v1/gamma/NVDA

{
  "symbol": "NVDA",
  "as_of": "2026-07-24",
  "spot": 202.0599,
  "spot_date": "2026-07-27",
  "gamma": {
    "net": -145282980,
    "gross": 1105957748,
    "ratio": -0.131,
    "regime": "negative",
    "flip": 203.93,
    "flip_vs_spot_pct": 0.93,
    "flip_status": "resolved",
    "contracts_used": 707,
    "heaviest_strikes": [
      { "strike": 202.5, "gex": -131948584, "share": 0.119 },
      { "strike": 200.0, "gex": -118124998, "share": 0.107 },
      { "strike": 220.0, "gex": 60411862, "share": 0.055 }
    ],
    "by_expiration": [
      { "expiration": "2026-07-27", "net": -156005869, "abs": 227532667 },
      { "expiration": "2026-07-29", "net": -7917163, "abs": 39581474 },
      { "expiration": "2026-07-31", "net": 19933259, "abs": 264030334 }
    ]
  },
  "method": "Black-Scholes with zero rate and zero dividend, implied volatility solved from the bid/ask mid of each contract's end-of-day quote, then gamma x open interest x 100 x spot^2 x 1%, calls positive and puts negative. The flip level is the zero crossing nearest spot on a 0.9x-1.1x grid. This is an estimate that assumes dealers are long every call and short every put — a convention, not a measurement.",
  "note": "An estimate, not observed data — see method. Open interest settles overnight, so this cannot update intraday whatever the timestamp suggests. Positive net gamma is associated with hedging that leans against price, negative with hedging that leans with it; that is a description of a mechanism, not a forecast and not a directional recommendation. We have not published a measured hit rate for these levels.",
  "disclaimer": "Educational analytics, not investment advice."
}

Read the snapshot as an estimate, not a tape print: net GEX is negative under the stated convention, the nearest modeled zero crossing is 203.93, and the result is dated to the 2026-07-24 settlement. The API does not turn those fields into a prediction.

What the sign describes

regime: positive

Estimated hedging leans against the move

Under the endpoint’s position convention, a price rise implies selling some hedge and a fall implies buying some back. That mechanism is associated with counter-move hedging.

regime: negative

Estimated hedging leans with the move

Under the same convention, a price rise implies buying more hedge and a fall implies selling. That mechanism is associated with same-direction hedging.

“Associated with” is deliberate. The endpoint estimates positioning from public chain data; it does not observe dealer books, forecast volatility or say which direction price will move.

Use it for depth or breadth

Monitor one symbol’s market temperature

Revisit the same ticker after each settlement. Track whether the regime changes, whether the estimated flip moves relative to spot, and which expiration or strike carries the concentration. This is a context series, not an alert by itself.

Compare a watchlist with one schema

Call the supported stocks and ETFs you care about, then compare regime, ratio, flip_status and concentration with the same field names. An agent can screen broadly without pretending the absolute GEX dollars are directly comparable across differently sized underlyings.

A first request for an uncached symbol can return 202 with retry_after_seconds: 90. Retry that request after the stated delay. Thin chains, rejected symbols, unusable quotes and failed lookups are not charged.

Freshness: the inputs settle overnight

Both open interest and the contract quotes used to solve implied volatility are end-of-day inputs. The endpoint computes from the latest available settled snapshot; it cannot see same-day opening, closing or rolling activity. Store and cite as_of. If the upstream source is unavailable and a prior snapshot exists, the response carries stale: true and a stale_note.

Method: useful because the assumptions are visible

For each contract the service takes the end-of-day bid/ask midpoint, solves implied volatility with Black–Scholes using a zero interest rate and zero dividend, and calculates gamma. It then computes gamma × open interest × 100 × spot² × 1%, treating calls as positive and puts as negative. The zero gamma level is the nearest sign change on a grid from 90% to 110% of spot.

The dealer side is assumed, not observed. Open interest says how many contracts exist; it does not reveal who is long or short. Quant Data follows the convention that dealers are long calls and short puts. Another provider can use a different convention, rate, dividend or volatility solver and publish a different flip level without either result being a direct observation.

Honest limits

US equity and ETF options only

Hong Kong, A-share, futures, FX and crypto symbols return 400. Cash-settled index roots do too; use SPY, QQQ or IWM instead of SPX, NDX or RUT.

Quotes must be usable

The option chain must meet the Max Pain liquidity rule and at least 100 contracts must have a usable quote and solvable implied volatility. Deep in-the-money or badly quoted contracts are skipped. When Gamma cannot be estimated, /v1/maxpain may still work.

A null flip is not missing data

Read flip_status. no_sign_change_within_10pct means the estimate kept one sign across the modeled range. Do not substitute the nearest strike or spot.

No measured hit rate

Quant Data has not published a success rate for the flip or heaviest strikes. They are estimated positioning levels, not validated targets, support or resistance.

Frequently asked

What does the Gamma API return?

It returns estimated net and gross gamma exposure, their ratio, a positive or negative regime, the zero gamma level when a crossing exists, the five strikes carrying the largest absolute GEX, and a breakdown by expiration. Add by_strike=true for the strike-level profile.

Is dealer gamma observed data?

No. Open interest does not reveal who owns each side of a contract. The endpoint follows a stated convention that dealers are long calls and short puts, solves implied volatility from end-of-day quote mids, then estimates gamma with Black-Scholes. The method and warning travel in every response.

What does positive or negative gamma mean?

Under the stated convention, positive net gamma is associated with hedging that leans against a price move; negative net gamma is associated with hedging that leans with it. That describes a possible mechanism, not a forecast of direction or volatility.

What does a null gamma flip mean?

It can be a valid result. When flip_status is no_sign_change_within_10pct, estimated net gamma keeps one sign across the grid from 90% to 110% of spot, so there is no crossing to quote. A chain too thin to estimate is returned as an error instead.

What is the difference between the free GEX pages and this API?

The free pages are nightly HTML snapshots for a curated ticker set and need no key. The commercial Gamma API returns structured JSON on demand for any supported US stock or ETF, including optional strike-level data, so an agent can monitor one symbol or compare a watchlist. A free API key lets you test the commercial endpoint first.

Is this a SpotGamma alternative?

It depends on what you are replacing. SpotGamma is a subscription research platform built around dashboards and written interpretation; the Quant Data Gamma API is a raw JSON endpoint — one symbol in, estimated net and gross GEX, regime, zero gamma and the heaviest strikes out, with the estimation method and its assumptions published in full on the methodology page. If you want charts and commentary, a platform serves you better. If you want reproducible numbers that a script, backtest or AI agent can consume directly, that is what this endpoint is for.

Can an AI agent use the Gamma API?

Yes. An agent can call one URL with an X-API-Key header, check as_of, regime and flip_status, surface the method and disclaimer, and respond to structured 202, 400, 404 or 503 states without inventing a value.

Try the Gamma API with your own ticker

One email gets a free qd_ key with 10 successful calls per UTC day across Gamma, Max Pain, Brooks Events and Weis / Wyckoff. No account or card. Upgrade only when you need sustained, batch or unattended access.

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Paid access starts with 3 days free after a card is added. The Max Pain and GEX pages stay free and need no key at all.

Read the full API reference →

Questions first? quantdata@quantdata.uk — a person reads it.

Educational analytics, not investment advice. The endpoint estimates options positioning and makes no forecast, recommendation, target or claim about future price or volatility.