Delta Volume

Delta splits volume by aggressor. A trade that lifts the ask is counted as buying, because the buyer hit the resting offer. A trade that hits the bid is counted as selling. The difference is delta. Positive delta says more volume paid up than sold down. This is closer to "buyers versus sellers" than OBV is, and it is still an estimate. A buyer can lift the ask to close a short. A seller can hit the bid to exit a long. Aggression is not the same as a new directional position. You need a feed that marks bid and ask. Candle volume cannot be delta.

Read delta against the bar's result. Price up and delta strongly positive is agreement. Price up and delta flat or negative is a divergence: the close rose even though more volume hit the bid, or the rise was a lack of offers rather than aggressive lifts. At a high, heavy positive delta that cannot push price, absorption, says offers are soaking up the aggression. At a low, heavy negative delta that cannot extend says bids are absorbing. Absorption is a location tool. It fails when the absorber steps away.

Negative delta into a low that then reverses, absorption at support, is a bullish footprint read. Positive delta on a breakout through resistance, with price holding the level, agrees with the break. Delta without a level is just a number that flips every bar.

Positive delta into a high that stalls is the bearish absorption read. Negative delta on a breakdown agrees with the break. A single bar of extreme delta is a candidate for a climax or for a continuation. The next bar is the tie-breaker. Do not short every positive spike.

Trusting delta on a feed that guesses aggressor with a tick rule. In fast markets the quote and the print are out of order and the sign flips. Also equating positive delta with "institutions are buying." You cannot see the account. You can see who crossed the spread.

Delta ignores resting size that never traded and ignores cancels. A wall of offers can disappear without a negative print. And bar delta hides the sequence inside the bar. A bar can be +5,000 because of the last second after being negative all the way down. Footprint charts exist to show that sequence. The single number does not.