Intro to order flow
A clear intro to order flow: what it shows about aggressive buyers and sellers, how delta and footprint charts read pressure, and what it cannot promise.
Part of the Market Mechanics: Orders and Execution track on Agenticks. About 9 minutes, written for a intermediate reader.
A price chart shows you the result of trading: where price ended up over each bar. It does not show you the fight that produced it. Order flow is the study of that fight, the actual buying and selling hitting the market rather than just the line it leaves behind. Every print on the tape is a buyer and a seller agreeing on a price. So why does price move at all? Because one side is more eager than the other. Order flow tries to make that eagerness visible.
Someone always crosses the spread
Resting limit orders sit and wait. Price only moves when an impatient trader sends a market order and takes the resting offer or bid. That impatient side is the aggressor. Order flow is mostly about reading who is choosing to be the aggressor, and how hard.
Picture the order book. Buyers post bids below the current price, sellers post asks above it. These resting orders are passive: they offer liquidity and wait their turn. An aggressive buyer is someone who refuses to wait and lifts the ask. An aggressive seller hits the bid. The words passive and aggressive here are not about emotion, they describe who initiated the trade. When aggressive buyers keep lifting offers faster than sellers can refill them, price ticks up. When aggressive sellers keep hitting bids and clearing them out, price ticks down. A plain candlestick only shows you the net result of that exchange. Order flow watches the tug of war trade by trade, so you can see whether a green bar was relentless buying or just a thin market drifting higher on low volume.
So why bother looking under the hood? Because the same candle can mean very different things. A bar that closes up an inch on huge buying that keeps getting absorbed is a different story than a bar that closes up the same inch on light, one-sided buying with no resistance. Price alone cannot separate those two. The activity behind the move can. That extra detail is the entire appeal of order flow, and also where most beginners get burned. It is tempting to treat a single big delta print or one absorption event as a reason to act. In practice the signal is faint and the noise is loud. Order flow is best used as confirmation or context around a level you already cared about, not as a standalone reason to trade.
Delta measures the balance of pressure
Delta is the simplest number that summarizes order flow: volume that traded into the ask (buyer initiated) minus volume that traded into the bid (seller initiated) over a bar. Positive delta means aggressive buyers did more; negative delta means aggressive sellers did. It is a quick read on which side pushed harder.
Two common tools build on this idea. A footprint chart breaks each candle open to show how much volume traded at every price inside it, usually split between buyers and sellers, so you see the activity a normal candle hides. Cumulative delta plots a running total of delta across the session, so you can watch pressure build over time. A powerful pattern is when these tools disagree with price. If aggressive sellers keep hitting a level with heavy volume but price refuses to fall, that is absorption: a large passive participant is quietly buying everything thrown at them. Order flow can surface that. It does not tell you what happens next.
Order flow describes, it does not predict
This is the honest part. Order flow shows you who was acting and how aggressively, in the past tense. It is rich context, but it is noisy, easy to misread, and the book can be spoofed or pulled in an instant. Treat it as one lens on the market, never a guarantee of the next move. Nothing here is financial advice.
Order flow is mainly trying to show you which of these? Which side is acting more aggressively, the buyers or the sellers Exactly. Price moves when one side crosses the spread more eagerly. Order flow reads that aggression trade by trade.
- Order flow
- The study of actual buying and selling hitting the market
- Delta
- Buyer-initiated volume minus seller-initiated volume in a bar
- Footprint chart
- A candle broken open to show volume at each price inside it
- Absorption
- Heavy selling or buying that barely moves price
Put the steps in the order that makes price tick up by one level.
- Sellers rest limit orders (offers) at the ask
- An aggressive buyer sends a market order and lifts the offer
- The resting offers at that price get filled and cleared out
- The best ask moves up to the next price level
ask bid buyers
You can read the basics of order flow
You now know that order flow studies the aggressive buying and selling behind price, that delta summarizes the balance of pressure, and that it describes what happened rather than predicting what comes next.
Common questions
- What is order flow in trading?
- Order flow is the study of the actual buying and selling hitting the market, not just the price that results from it. It looks at which side is acting more aggressively and where trades are stacking up.
- What is delta in order flow?
- Delta is the difference between volume that traded into the ask (buyer initiated) and volume that traded into the bid (seller initiated) over a bar. Positive delta means aggressive buyers were more active; negative delta means aggressive sellers were.
- Does order flow predict the next move?
- No. Order flow is descriptive, not predictive. It shows who was acting in the market, and it can be misread. It is context, not a signal, and nothing here is financial advice.
Terms defined in this lesson
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