Definition

Scaling Aggression

A meaningful increase in aggressive order flow that overwhelms liquidity capable of absorbing smaller waves.

Full Explanation

Scaling aggression describes a simple possibility traders often overlook: the liquidity may not have become weaker at all. The aggression arriving this time may simply be larger.

A price can absorb several modest waves of buying or selling and then relocate when a much larger wave arrives. The resting liquidity could be similar to what was present before, but every shelf has a limit. If incoming aggression exceeds that capacity, execution has to move to other prices.

This is one of several reasons a level that held previously may break later. Consumption may have reduced the resting orders. Participants may have withdrawn them. Or aggression may have scaled beyond what the existing liquidity can handle. The chart records the outcome — absorption or relocation — but it cannot reliably tell you which hidden change caused it.

In the Book 1 chapter

Chapter 4 · The Mechanics

The Living Order Book

There’s a belief that floats around trading communities, stated so often it’s become assumed wisdom: if a level has been tested multiple times, it’s getting weaker. The idea is that each visit to a level chips away at the liquidity sitting there — buyers or sellers getting used up — and eventually there won’t be enough left to hold, and the level breaks.

From the Blog 1 post

The Fallacy of "Key Levels" (And the Myth of "Strength")

A price level is just a number. Its significance comes entirely from the orders sitting at it right now—and those orders change constantly.