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Order flow
Working definition
The stream of orders arriving at a market — aggressive orders consuming resting size and passive orders posting it — and, by extension, the discipline of reading that stream from book and tape data.
Order flow is the family name, and half its trouble is that the family’s poorest relations borrow it most.
Used precisely, the term names the stream itself: orders arriving at a market — the aggressive ones crossing the spread to consume resting size, the passive ones posting, revising and withdrawing it — and everything a market’s price does is downstream of the meeting between those two populations. The discipline built on the term is the measurement of that stream from recorded data, and this glossary carries its instruments one by one: cumulative delta signs and sums the aggression; the footprint chart keeps its per-price ledger; order flow imbalance measures the pressure of arrivals and cancellations on the book; depth of market and quote fade watch the resting side’s promises and betrayals; and the absorb/sweep balance names the meeting itself at the touch.
The precision matters because the term travels without its measurements. The smart money school speaks fluently of order flow while working from candle geometry alone — no book, no tape, no per-trade record — and the borrowed authority is the point of the borrowing: flow sounds measured. The distinction this entry exists to hold is not a snobbery about schools but a checkability line: a flow claim that traces to recorded book or tape data under stated conventions can be verified by a second person; one inferred from candle shapes is an interpretation, whatever vocabulary it wears. Both may be interesting. Only one is a measurement. Anything marketed as order flow trading should be read against that line — the phrase spans both practices, and which side a given tool or course sits on is answered by asking what data it actually reads.
The family’s shared caveat applies at the root: in over-the-counter FX there is no consolidated stream. Every flow measurement is a measurement of somebody’s slice — one broker’s book, one aggregator’s tape — and honest tooling names its feed the way this site’s own tick provenance discipline demands.
And the family’s shared boundary applies too. The measurements are real, reproducible, and frequently beautiful; whether any of them predicts price at a horizon anyone can trade is a separate question per instrument, per convention, per venue — answered in evidence under the two lenses, never by the resonance of the word flow.
Commonly confused with
Neighbouring concepts that get used interchangeably, and the distinction that actually separates them.
- Order flow imbalance
The imbalance is one measurement extracted from the flow — the net of arrivals, cancellations and executions pressing on the book. Order flow is the stream itself; the imbalance is a statistic computed over it, one of several this family defines.
- Volume
Volume is the flow's least informative summary: everything that traded, unsigned and unplaced. The flow vocabulary exists precisely to recover what volume discards — side, aggression, location and sequence.
- Smart money concepts
The SMC school uses "order flow" for inferences drawn from candle geometry alone — no book, no tape, no per-trade data. Used precisely, order flow names measurements of recorded market data; the borrowed usage keeps the vocabulary and drops the measurements.
- Tape reading
The older craft name for the same instinct: watching prints for size, pace and insistence. Modern order-flow tooling is tape reading with recorded data and stated conventions — the difference is not the idea but the checkability.
How to measure it in your own data
A definition you cannot test is a definition you have to take on trust. This is the shortest honest route from the concept to a number you computed yourself.
- Records you need
Recorded per-trade data and order-book updates — prices, sizes, sides, timestamps — from an identified feed, since OTC FX has no consolidated stream and every flow measurement is a measurement of somebody's slice.
- What you compute
The family's instruments, each with its own entry: aggressor-signed sums (cumulative delta), per-price transaction ledgers (footprint), book-pressure statistics (order flow imbalance), resting-size behaviour (depth of market, quote fade), and the absorb/sweep balance at the touch.
- What the answer tells you
Order flow is not one signal but a layer: the tell is whether a claimed "flow" reading traces to recorded book or tape data under stated conventions. Where it does, one of this family's instruments is at work; where it does not, the term is decorating an inference made from candles.
Questions and answers
What is order flow in trading?
The arriving stream of orders — aggressive ones crossing the spread and consuming resting size, passive ones posting and withdrawing it — and the discipline of measuring that stream from tape and book records. Every instrument in this glossary's microstructure family is a lens on some part of it.
Is order flow trading the same as ICT order flow?
No. The ICT and smart-money usage infers "flow" from candle shapes without book or tape data — a legitimate school with its own entries here, but a different object. Precise usage reserves the term for measurements of recorded market data under stated conventions.
What data do you need to read order flow?
Recorded per-trade prints and book updates from an identified feed. In spot FX that identification is not pedantry: with no consolidated tape, flow measurements are feed-relative, and two books can tell different stories about the same minutes.
Does order flow analysis work?
Its measurements are real — delta, imbalance, depth behaviour are all computable and reproducible. Whether any of them predicts price at a tradeable horizon is instrument-by-instrument, convention-by-convention, and measured rather than assumed; this family's entries each state that boundary for themselves.
Related terms
Derived from the links this entry makes and the entries that link back to it.