Arbitrage scanner

Prices are each venue's best ask at the top of the book — the price a buy fills at, not the last trade — with no depth or slippage. Polymarket's second side is priced at 1 − its best bid, as on its own Buy button. Fees are taker fees from each venue's published schedule (Kalshi 0.07 × P × (1 − P) per share, scaled by the series' multiplier; Polymarket the market's own rate × P × (1 − P)); “est.” marks a leg still on the published default rate. A match means both venues state the same proposition — open the event to compare how they word its settlement. Pairs the two venues price on opposite sides of 50% are not listed: two books quoting one proposition cannot differ by half the payout, so such a row is a market matched to the wrong side, not a price.