Gamma Exposure (GEX) Trader Tool

| U.S. market live options gamma exposure by strike | Market status: Unknown

API keys ▾

Massive API key

Stored only in this browser's local storage. Sent only to api.massive.com.

FRED API key

Stored only in this browser's local storage. Sent to a local proxy on your machine (localhost:8787, see fred_proxy.js) which forwards it to api.stlouisfed.org — required because FRED's API blocks direct browser requests.

Finnhub API key

Stored only in this browser's local storage. Sent to the same local proxy (localhost:8787), which forwards it to finnhub.io — Finnhub's API blocks direct browser requests too.

Watchlist ▾

No symbols yet. Load a chain and click "Add to watchlist".

Transactions ▾

No positions yet. Use "Open" on a watchlist row to record one.

Ticker

Expiration

Auto-refresh every 60s

Auto-refresh off

Load a ticker to see company info.

Calendar & news ▾

Earnings and economic calendar

Next earnings

Load a ticker, and enter/save your Finnhub API key, to see its next earnings date.

Economic calendar (next 7 days)

Enter and save your FRED API key, and run fred_proxy.js locally, to load the economic calendar.

Ticker news

Enter and save your API key, then load a ticker to see news.

Gamma exposure

Total net gamma exposure

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Load a ticker to begin

Spot price

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Underlying last price

Call wall (CR)

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Put wall (PS)

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Gamma flip / HVL

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Enter a ticker and click "Load chain" to get started.

Net open interest

Enter a ticker and click "Load chain" to get started.

Methodology. Per-strike exposure = gamma × open interest × 100 × spot² × 0.01, using gamma as reported by Massive for each contract at the current spot. Calls are counted as positive (dealers assumed long gamma / long calls) and puts as negative (dealers assumed short gamma / short puts) — this is the standard convention used by most public GEX dashboards, not a verified read of actual dealer positioning. Call wall (CR) = the strike above spot with the greatest positive net gamma (resistance); put wall (PS) = the strike below spot with the smallest (most negative) net gamma (support). Both are searched within ±25% of spot first, since open interest parked at extreme, far-dated-feeling strikes can otherwise dominate the calculation without reflecting current dealer hedging pressure; if no qualifying strike exists in that range, the search falls back to the full chain. A secondary level (CR2/PS2) is shown whenever a qualifying strike exists beyond the primary wall: CR2 is the strike with the highest net gamma among strikes above CR, and PS2 is the strike with the lowest net gamma among strikes below PS — unbounded in distance, so it's simply the strongest opposing extension past the primary wall, wherever it falls in the chain. It's shown as a lighter, thinner line on the chart and a "2nd" value on the card. Gamma flip (a.k.a. HVL, "High Volatility Level" — the same concept under different names) is the hypothetical spot price at which total dealer gamma crosses zero; it's computed by re-deriving each contract's Black-Scholes gamma across a range of hypothetical spot prices using its strike, time to expiry, and Massive-reported implied volatility, then finding the zero crossing. If implied volatility isn't available for enough contracts, it falls back to a cruder approximation (cumulative net gamma by strike at the current spot). The chart shades the area below the flip red (negative-gamma / momentum regime) and above it green (positive-gamma / mean-reverting regime). This tool is for research and informational purposes only — not investment advice.

Data refreshes every 60 seconds for the selected expiration. The expiration list is fetched once per ticker. Greek and quote data availability depends on your Massive plan tier. Spot price is pulled from stockanalysis.com's public quote endpoint (no key required) since it's typically more current than the underlying price bundled in an options snapshot; if that lookup fails for a given symbol, the tool falls back to the price reported by Massive and labels the card accordingly. The market status indicator in the header comes from Massive's market status endpoint and refreshes every 60 seconds once an API key is saved. The company info panel (logo + short description) and the news panel both load once an API key is saved and a ticker is loaded: company info from Massive's ticker reference endpoint, and news from Massive's news endpoint, scoped to the loaded ticker and showing its 15 most recent articles, newest first. The API keys panel is a standalone, collapsible section at the top of the page (click its header to expand or collapse it; the state persists across reloads). Below it, ticker/expiration controls sit in a two-column row next to the company info panel. A second two-column row pairs the earnings/economic calendar panel with the news panel; this second row has its own "Calendar & news" header and can be collapsed independently of the API keys panel, with its state likewise persisted across reloads. Both panels in that row are capped at a fixed height and scroll their own content internally if it doesn't fit. Below that, a "Gamma exposure" label introduces the summary cards and the strike chart. News article links open the original publisher's page in a new tab; this tool doesn't host or vouch for that content. The earnings and economic calendar panel has two parts. "Next earnings" shows the loaded ticker's soonest upcoming earnings date, reported period, and consensus EPS/revenue estimates, from Finnhub's earnings calendar endpoint, scoped to that symbol over the next 60 days; Finnhub doesn't expose a distinct "full fiscal year" flag on this endpoint, so the period is always shown as year + quarter (e.g. "2026 Q2"), matching what Finnhub's own calendar displays. "Economic calendar" lists upcoming U.S. economic data releases for the next 7 days (release name and date) from the Federal Reserve's FRED API, independent of the loaded ticker; the request sets include_release_dates_with_no_data=true, since FRED excludes future release dates lacking published data by default — without it, a forward-looking window like "next 7 days" would always come back empty. Both Finnhub and FRED require their own separate API key, each entered and stored the same way as the Massive key (its own password-masked field, saved only to this browser's local storage). Unlike Massive, neither FRED's nor Finnhub's API sends the header browsers require to allow direct cross-origin requests (CORS), so this panel can't call either host straight from the page — typing one of their URLs into the address bar works because that's a plain navigation, not a script-driven fetch, and CORS only restricts the latter. Instead both calls go through one small local proxy, fred_proxy.js, shipped alongside this file: run node fred_proxy.js in a terminal before using this panel, and leave it running. The proxy only relays requests to api.stlouisfed.org and finnhub.io and runs entirely on your own machine, so neither key reaches any other third party.

The solid white line marks current spot. Each bar shows net (call+put) gamma exposure for that strike, colored green for positive and red for negative — hover a bar to see the call, put, and net values separately. The dollar-value axis on the left is fixed in place and doesn't scroll; only the bars underneath it move. Bars are a fixed width so strikes stay readable on wide chains — scroll the chart horizontally to see more; it re-centers on spot after every load and refresh, even if the strike axis returned by a new chain snapshot shifts. A marker whose value falls outside the plotted strike range is shown with a ◀/▶ arrow rather than collapsing onto the chart's edge. For very near-dated expirations (0DTE/1DTE), the gamma-flip sweep narrows its search window to the option's expected move so it isn't undersampled by a too-wide, too-coarse scan.

Below the gamma chart, the "Net open interest" chart shows the same strikes with net OI (call open interest minus put open interest) instead of dollar gamma exposure — green where calls outnumber puts at that strike, red where puts outnumber calls. It reuses the same spot/call-wall/put-wall/flip reference lines as the gamma chart (without the red/green gamma-regime background, which is specific to dealer gamma, not OI) and its own axis is likewise pinned to 0 at the vertical center and a plain contract count (not a dollar value) on the left. Both charts re-center on spot independently after every load/refresh, and scrolling either one horizontally scrolls the other to match, so the two stay aligned strike-for-strike for side-by-side comparison.