Reading the result
Read each venue on its own terms. On Kalshi, 60,761 settled whale buys won 74.4% of the time and returned -1.6% on stake gross, across 48,808 markets at about 2.2 trades per market. On Polymarket, 181,686 settled whale buys won 61.8% of the time and returned -0.8% on stake gross, across 14,553 markets at about 14.6 trades per market.
A win rate says nothing on its own about return, because the entry price sets the payoff. Trades per market says how correlated the sample is: many buys in one market are many rows and one outcome. The unresolved share says how recent the tail is. Use the backtester to slice the same events by price band, size, category and trader rather than reading the pooled figure as a strategy.
Population and method
- Window. Detection time from 2026-09-10T00:00:00.000Z inclusive to 2026-10-10T00:00:00.000Z exclusive.
- Lane. Whale lane only: trades above each venue's size floor, whoever placed them. Tracked-lane trades by identified traders below the floor are excluded.
- Eligibility. buy_yes and buy_no with a recorded price strictly between 0 and 1. Invalid prices are counted and excluded.
- Scoring. Resolution observed at export time: win, loss, void or unresolved. Only wins and losses enter the rate and the PnL.
- Stake. $100 per eligible settled buy, filled at the recorded price, held to settlement. PnL is 100 / price − 100 on a win and −100 on a loss.
- Not modelled. Fees, spread, slippage, entry delay, partial fills, depth, position limits, capital lock-up, and correlation between trades in the same market.
- Categories. Reported as unknown because labels were not verified for research use at export. No category claim is made.
- Export. One read-only, repeatable-read transaction against the production history, so every count comes from the same instant.
The full definitions, including the settlement rule and the payoff arithmetic, are on the methodology page.