Where can I get free GEX (gamma exposure) data?

What the free GEX data covers

FinzData publishes point-in-time gamma exposure for 11,200+ US single stocks, ETFs and the major indexes, with history back to 2010. Every row carries the levels traders actually trade against: the gamma flip, the price where dealer gamma changes sign — above it moves tend to be damped, below it moves can accelerate; the call wall, the strike with the largest call gamma, often resistance; and the put wall, the strike with the largest put gamma, often support.

• Net, call and put gamma
• Call and put open interest and put/call ratio
• ATM implied volatility and contracts used

Because it is point-in-time, the levels for a past date are the levels that existed then, not a recompute from today's chain. See the full dataset at point-in-time GEX and today's free levels at GEX levels today.

How to get it: CSV, API and MCP

Getting the data takes minutes:

1. Free API key — sign up with just an email at finzdata.com and call the REST API at https://api.finzdata.com. The free key includes the last 30 days of daily GEX, the last 12 months of daily US stock bars, COT, SEC fundamentals, US macro series and 13F holdings, with 1,000 data calls a day.
2. CSV downloads — buy a market once and download its full history.
3. MCP server — point ChatGPT, Claude or any AI agent at https://api.finzdata.com/mcp and ask for gamma exposure levels in plain language.

Server-side backtests and free indicators for TradingView, thinkorswim, NinjaTrader and more round out the delivery options.

Why point-in-time data avoids backtest pitfalls

Most free gamma exposure numbers floating around are recomputed after the fact: chains get corrected, strikes appear or vanish, and the levels your backtest tested were never the levels you could have traded. FinzData's GEX is point-in-time, so any past date returns the option chain as it stood that day.

The same discipline runs through everything you can pair with GEX: 16,000+ US stocks since 2000 with delisted names included, so it is survivorship-free; 139 futures markets with every contract since 2007; COT since 1986; SEC fundamentals as filed, with no look-ahead bias; and 18,000+ macro series with every vintage kept, so CPI, jobs, GDP and rates revisions never leak into a backtest.

That means a gamma flip strategy is tested against what the market actually knew on each day.

What it costs and what is free

The free tier is generous: an API key costs nothing and needs only an email. It includes the last 30 days of daily GEX, the last 12 months of daily US stock bars, COT, SEC fundamentals, US macro series and 13F holdings, and 1,000 data calls a day.

Full history is a one-time purchase at finzdata.com/shop — you buy once and keep the data, and one futures market with its full history is $39. The dataset catalog at finzdata.com/datasets lists every market.

If you only want today's numbers, free daily gamma exposure levels are published at gex-levels-today, including the gamma flip, call wall and put wall for the major indexes.

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