Put wall

Also called Put gamma wall, gamma support, put support

The strike with the most negative net dealer gamma exposure in the chosen expirations.

The put wall is the strike holding the most negative net gamma exposure: calls and puts at the strike together, from the dealer's side. Ties go to the strike nearest spot. If no strike has negative net GEX, there is no put wall.

How to read it

Under the positioning model, dealers are short the puts investors buy for protection, so heavy put open interest shows up as negative gamma. Traders often read the put wall as support, where protective put hedging is concentrated. If price breaks through it, dealers short gamma there may sell into the drop, which is why a break of the put wall can speed up.

The put wall can sit above spot as well as below it. The strip shows its distance either way.

A caution for single stocks

In single names, investors often sell puts rather than buy them, which would leave dealers long those puts. A single stock's put wall is the least certain of the levels. See where the estimate breaks.

Where it appears

The red rule on the price chart and exposure by strike, the strip, and the Levels card. The strike selector and wheel and income use the picked expiration's own put wall for short puts.