A footprint chart describes past trades, and a forecast needs a test
A footprint chart divides each bar by price. At every price it shows how much traded when the trade hit the bid and how much when it lifted the ask. Order flow is the same idea over time: net buying and selling, large prints, and how the book responded. Both describe trades that have already happened.
The chart shows how one bar is read. Charting software tags each trade as at the bid or at the ask by comparing its price with the quote, and the difference is the imbalance at each price. A price that trades heavily with little move is sometimes called absorption, and a run of one sided prints is called pressure. Those are names for a pattern, not a proof of what comes next.
The claim that matters is the forecast. Public data does not show who is behind a trade, whether it was a hedge, a spread leg or a directional bet, or whether the same flow would come again. The academic study that found a link between option order flow and later prices used a data set that tags each trade as opening or closing a position, and public feeds do not carry that tag.
A fair answer is that the charts help in reading a session and in building a question to test. Whether they add anything after costs is not settled for Indian index options with public data. Any test must be dated, costed, and run on data the rule did not see when it was built. The build up question shows the same caution for open interest.
Before you trade. Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. Read the SEBI study