Order-flow analysis studies executions and, where available, changes in the order book. A time-and-sales window, footprint chart and depth ladder display different parts of that information. None provides a complete view of every participant's positions or intentions.

Its value as a research tool depends on accurate data definitions. Saying that buying exceeded selling is especially easy to misunderstand: every completed trade has both a buyer and a seller.

Aggressive buying is a classification, not extra buyers

An incoming order that immediately matches resting liquidity is commonly called an aggressor. It may be a market order or a marketable limit order. CME's order functionality documentation describes how aggressing orders interact with the book.

A platform may label volume as buyer-initiated or seller-initiated using exchange messages or its own classification method. Trade delta usually compares those classified volumes. It does not subtract the total number of shares bought from the total sold, which would ignore that both sides exist for every execution.

Check whether the feed supplies the relevant classification and how the software handles ambiguous prints. Aggregation rules, session boundaries and missing data can change the displayed result.

Resting depth and completed trades answer different questions

Depth shows displayed interest available at a moment. Time and sales reports transactions that have already occurred. A footprint groups executed volume by price and period under the platform's chosen rules.

For a hypothetical example, 800 contracts classified as aggressive buys and 500 as aggressive sells produce a positive delta of 300 for that interval. The arithmetic says nothing by itself about whether price must rise next. Passive sellers may have supplied enough liquidity to absorb that buying, or prices may already have moved before the interval ended.

Likewise, a large displayed bid can be canceled before it trades. Hidden quantities may be absent from the visible book. Our Level 2 guide explains coverage and visibility limits.

Absorption is an interpretation that needs a definition

Traders sometimes use absorption to describe substantial aggressive trading with limited further price movement. To research it, specify what counts as substantial, how far price may move and the observation interval.

A screenshot showing repeated trades at one price can support a description of that interval. It does not establish the identity of the passive participant, prove a large institution is accumulating or guarantee a reversal. Continued trading can eventually exhaust the liquidity, or new orders can replenish it.

Avoid explaining the same pattern as bullish after a rally and bearish after a decline. Record the proposed interpretation before the outcome and retain the failures.

Check the market and the feed

A listed futures contract has an exchange-defined trading environment, but your subscription and software still determine the view delivered. Equity trading can span multiple venues. An OTC foreign-exchange broker's activity is not the entire global currency market.

Before buying software, identify the market-data entitlement, historical tick availability, replay behavior and exchange coverage. A visually detailed chart built from limited or differently classified data is not necessarily comparable with another platform's chart.

FAQ

Does order flow reveal who is trading? Usually it describes orders and executions, not the beneficial owner's identity or overall strategy.

Is positive delta automatically bullish? No. It describes a classification of past executions within the selected interval.

How long does it take to learn? There is no reliable timetable to mastery or profitability. Start by understanding the feed and verifying the calculations.

Key Takeaways

  • Distinguish aggressor classifications from the existence of both trade sides.
  • Separate displayed liquidity, executions and interpretation.
  • Define hypotheses before observing outcomes and account for feed limitations.