Absorption
Absorption occurs when large passive limit orders absorb aggressive buying or selling without allowing price to move. It signals that a well-capitalized participant is taking the opposite side of the aggression and is one of the most reliable reversal signals in order flow analysis.
Absorption is the process by which large passive limit orders neutralize aggressive market orders at a specific price level, preventing price from moving despite sustained buying or selling pressure. The absorbing participant is effectively offering unlimited liquidity at that level: taking the other side of every aggressive order that arrives.
What absorption looks like
Sell absorption at resistance: buy aggressor volume is high (fast tape, large prints hitting the ask, rising delta), but price is not advancing. Each aggressive buy is being matched by a large passive seller who keeps refilling at the same price. The DOM shows a large ask that is not being lifted despite heavy buying.
Buy absorption at support: aggressive selling is relentless but price is not falling. A large passive buyer is absorbing every sell order, holding the level.
How to identify absorption
Time and Sales: large buy prints appear repeatedly at the same price, but price does not advance to the next tick. The ask is being hit but not lifted.
DOM: a resting limit order that visibly refreshes (or appears much larger than normal) at the same level as price is being tested.
Cumulative delta divergence: the most common signal. Delta rises significantly (net buying aggression is high) while price fails to make a new high. The divergence between delta and price IS the absorption.
Footprint chart: the cell at the tested price shows very high ask volume (buyers were aggressive), but price did not move above it. The level was defended.
Why absorption matters
Absorption identifies where large, informed participants are positioned. If a large institution is absorbing buying at a resistance level, they are building a short position: and they have enough capital to hold that level. When the absorption is complete (their position is full), they let price drop.
This is among the highest-conviction order flow signals because it reveals not just direction of aggression but the response of a well-capitalized counterparty.