In plain terms
Order flow means analyzing the stream of events that forms a market: orders, amendments, cancellations, and executions. In trading jargon, the term is often used more narrowly for the tape, delta, and footprints built from completed trades.
How the term is used
Saying “I read order flow” does not identify one dataset. The order book shows visible liquidity still waiting; Time & Sales shows trades that occurred; delta and CVD are derived calculations. The full Order flow entry separates these layers and explains feeds and classification.
Limit
A feed may cover only one venue and omit hidden liquidity. When aggressor side is not published, the software may estimate it: the result does not automatically reveal identity, intention, or the future direction of price.
Sources
- CME Group, Order Functionalities — Order Aggressor Indicator — defines an aggressor order that immediately matches orders already resting in the book.
- Sierra Chart, Tick by Tick Data Configuration — distinguishes volume executed at the bid or ask from market-depth quantity.