Notional

Also called notional value · trade size

The dollar value of a trade or position — contracts multiplied by the price actually paid per contract.

Notional is not the maximum payout, and confusing the two makes every longshot look like a whale trade.

The correct calculation has a wrinkle on any two-sided venue: the price paid depends on which side the aggressor took. On Kalshi the tape reports a YES price for every print regardless of who initiated it, so a print where the taker bought NO has to be valued at one minus that price. Ten thousand contracts printed at a 95¢ YES price, taken on the NO side, is five hundred dollars of notional — not ninety-five hundred. This site computes it that way on every tape row, and the difference is the difference between a rounding error and a headline.

Notional is the unit that flow ranking runs on: series are ordered by total taker notional, and a series-level score is the notional-weighted average of its prints, so a hundred-dollar print cannot outvote a fifty-thousand-dollar one. Keep it distinct from volume, which is notional summed over a window, and from open interest, which counts contracts outstanding rather than dollars transacted.

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Definitions describe how Polymarket and Kalshi behave and how WhaleTracks models them; venue rules and fee schedules can change, so confirm anything you size a position on with the venue itself. WhaleTracks is informational analytics, not financial advice. Past performance does not guarantee future results.