Using Historical GEX Filters to Review Past Gamma Levels

Historical GEX filters are a premium feature that let you select past option expiration dates and see how gamma exposure was distributed at the time. Instead of only analyzing the current chain, you can replay how open interest was positioned by strike in previous cycles.

What Historical Filters Do

When you choose one or more historical expirations in the screener (or on the analysis page), the GEX calculations are rebuilt from the option chain as it existed for those dates, and price context is anchored to the same period.

• Backtest your own strategies using historical gamma exposure data
• Compare gamma exposure by strike against what happened afterward
• Line up gamma exposure with a specific expiration date across the chain

A Simple Backtesting Workflow

1. Pick a stock that had significant gamma walls in a prior cycle.
2. Select the historical expiration(s) you want to study.
3. Compare the significant GEX levels against where price actually traded into and through expiration.
4. Note what price actually did, not what the level implies it should do; our own year-long test found gamma walls no better than a coin flip at predicting next-day direction.

Things to Keep in Mind

• GEX levels describe positioning, not a forecast; confirm anything you see with price and volume.
• The one place our testing found a small, real effect is expiration day itself, where price closes near the expiring wall slightly more often than chance (10.9% vs. 10.2% for a fake level).
• Use several cycles before drawing any conclusion from a pattern you think you see.

Historical GEX filters require an active subscription. Upgrade to premium to unlock them, or head to the screener to start exploring.