GammaLens
Options gamma exposure, in your browser
Paste or upload an options chain and get Gamma Exposure by strike, Gamma Flip, Call & Put Walls and Max Pain, per expiry or all expiries combined. Completely free: no signup, no data feed, nothing leaves your browser.
Load a sample or your own chain to see the gamma map.
Educational tool only, not financial advice.
Option dealers hedge their delta. Gamma tells you how much that hedge must change when the underlying moves. GEX adds it up across every strike: gamma × open interest × 100 × spot² × 1%, counting calls as positive and puts as negative (the common assumption that dealers are long calls and short puts). The result is the dollar amount of hedging per 1% move.
The price where total dealer gamma switches sign. Above it dealers are usually long gamma and trade against moves (buy dips, sell rips), which tends to calm the market. Below it they are short gamma and chase moves, which tends to add volatility. GammaLens re-prices every option with Black-Scholes across ±25% of spot to find the zero crossing, so it needs IV and expiry dates in your file. Without them it shows no flip rather than a guess.
The strikes with the largest positive call GEX and the largest negative put GEX. Traders watch them as likely resistance (call wall) and support (put wall), because hedging flows concentrate there.
The settlement price at which option holders would collectively receive the least intrinsic value, meaning the most contracts expire worthless. It is a single-expiry idea: GammaLens computes it per expiry, and in the all-expiries view it shows the nearest expiry.
These are models with real limits. Open interest updates once a day, dealer positioning is assumed and not observed, and the levels describe hedging pressure. They do not predict price.
GammaLens reads the header row and recognises common broker column names. The simplest format is:
strike,expiry,type,open_interest,gamma,iv
580,2026-11-20,C,12500,0.0213,0.16
580,2026-11-20,P,9800,0.0213,0.16You need strike, type (C/P, Call/Put) and open interest, plus gamma or IV (decimal or %). With IV, an expiry date is required; expiry can only be left out of single-expiry files that include gamma.
spy-sample.csv · qqq-broker-iv-only.csv · spx-side-by-side.csv
$0
$9 one-time
From you. Export an options chain from your broker or a free source like the CBOE delayed quotes page and drop it in. GammaLens has no data feed and no server. Your file never leaves your browser.
No. GammaLens is an educational tool that applies public formulas to data you provide. Do your own research.
No. $9 once, and the key works on any browser you use.