Bid volume and ask volume

Bid volume is the quantity that traded at the bid price, initiated by sellers; ask volume is the quantity that traded at the ask, initiated by buyers. A footprint chart shows these two numbers side by side at every price of a bar.

Senzoukria · Glossary · Updated September 2026

Reading a bid × ask cell

In a footprint bar, each price level is a cell with two numbers. The left number is the bid volume, contracts sold aggressively into the resting bids at that price. The right number is the ask volume, contracts bought aggressively from the resting offers. Their difference is the level delta; their sum is the level volume.

Because a trade at the bid and a trade at the ask are separated by the spread, the natural comparison is diagonal: the ask volume at one price against the bid volume one tick lower. That is how buyers lifting the offer at a price compete with sellers hitting the bid just beneath it. Sierra Chart's default compares the two numbers of the same row instead; both conventions exist and a tool should say which it uses.

What the two columns reveal

  • Heavy ask volume with price rising: buyers are paying up and offers are giving way.
  • Heavy bid volume with price not falling: sellers are hitting bids and being absorbed.
  • A level with large volume on both sides is a contested price, often revisited.
  • A level with almost nothing on one side is a price the market moved through without a fight.
  • Zero on one side of a cell is a real reading only when the feed provides the split; on bars without aggressor data both sides are absent, not zero.

In Senzoukria

The Bid × Ask cell type is the default footprint view, and the guided tour introduces it by zooming into a candle: the left number is what sold at the bid, the right number what bought at the ask, price by price. The Buy/Sell Volume indicator draws the two sums of the bar as separate lines in a pane, which is the same data as the delta but with the two legs kept apart.

The footprint settings hold one bid colour and one ask colour shared by the cell types that keep the two sides apart; the heatmap page has its own pair for the ladder. The heatmap page shows the sizes inside the DOM ladder rows with the same numbers when the rows are tall enough to read.

Common mistakes

  • Confusing bid volume with volume resting on the bid. The first is executed, the second is waiting.
  • Reading the two numbers of a row against each other when the tool uses the diagonal rule, or the reverse.
  • Comparing raw numbers across contracts. A cell of a given size is small on ES and large on a micro.
  • Assuming a big ask number means buyers won. If price failed to move, someone sold all of it passively.

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Frequently asked questions

What does bid and ask mean on a footprint?
The bid number counts contracts that were sold aggressively at that price, hitting the resting bids. The ask number counts contracts bought aggressively, lifting the resting offers. Together they replace the single volume figure of a candle with a picture of who initiated the trading at each price.
Why compare ask volume diagonally with bid volume?
Because at any instant the best bid and the best ask sit one tick apart. Buyers who lift the offer trade at the higher price, sellers who hit the bid at the lower one, so comparing the ask at a price with the bid one tick below matches the two sides of the same auction. This is the ATAS convention and the one used for imbalances in Senzoukria.

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