A gamma wall is not an order book wall

Two objects with the same name

In the Heatmap course, a "wall" is a band of passive liquidity: contracts actually resting in the book, visible, that hold or pull. In this course, a "wall" is a strike where future hedging flow will be concentrated. Nothing is resting in the book. The gamma wall is a forecast of behavior; the book wall is an observation.

Confusing the two produces two symmetrical mistakes:

1. expecting passive liquidity at the call wall and trading it like a red band, when there may be nothing in the book at that price;
2. ignoring a real book wall on the grounds that there is "no gamma" at that level, when an institutional iceberg needs no gamma whatsoever to hold.