Core terms
Absorption
Trader usage for many shares printing at one price while the displayed size there holds, so price does not move. It describes trading that already happened at a level, not the next move.
Absorption has two observable parts: printed volume at one price on Time & Sales, and displayed size on Level 2 that does not shrink as fast as the prints. A countable version: at least 25,000 shares print at the same bid within 90 seconds while the displayed bid stays visible and nothing prints below it (Illustrative thresholds chosen for counting, not a standard).
The gap between prints and display fits several causes that look the same on screen: a reserve (iceberg) order refilling, several participants joining the price in turn, a market maker refreshing a quote, or non-displayed orders at that price.
Absorption ends in one of three ways: sellers stop and prints shift to the offer; the buyer stops and the bid shrinks; or the bid is pulled with few prints. The first can be followed by a bounce or by chop; in the other two the level is gone.
What traders should verify
Write the thresholds (shares, time window, price) before counting, and log every case that meets them, with how it ended and the result in R after costs.
Do not conflate
Trader usage; there is no official definition. Size that held for 90 seconds can keep holding or break a minute later, so the observation alone carries little information about direction. No FennEdge study measures absorption outcomes.
Primary source
Trader usage: there is no official definition, and platforms and tools may calculate it differently.