Walls that hold, walls that pull: the session's test

A wall is only an intention

A wall on the heatmap is a dense, visible liquidity band, an order or a group of orders far larger than the book's average. On the FDAX, that starts around 150 contracts on a level. But a displayed wall is not a defence: it is an intention, and an intention can be withdrawn before contact.

The Heatmap course set out the distinction between fresh and persistent liquidity. The DAX gives it an extra dimension: time. Because levels hold all day, a DAX wall has a history, and it is its history that tells whether it will hold.