arbitrage scanner

how arbitrage works

arbitrage opportunities occur when the same event has different prices on different platforms. you can't transfer positions between platforms — instead, you take opposite sides on each.

example: "team X wins" is priced at 45¢ on polymarket and 50¢ on kalshi. you buy YES on polymarket (45¢) and buy NO on kalshi (50¢). total cost: 95¢. one of them will always pay out $1 — guaranteed 5¢ profit regardless of outcome.

when we say "sell on kalshi" — we mean buying NO there, which is economically the same result.

raw vs net spread: the raw spread is the pure price difference between platforms before any fees. the net spread is what you'd actually profit after Polymarket fees (~0.4% for sports) and Kalshi fees (~7% * p*(1-p)). only positive net spread = real arbitrage opportunity.

bid / ask: bid (green) is the highest price a buyer will pay. ask (red) is the lowest price a seller will accept. the gap between them is the market spread.

important: always verify prices on both platforms before trading as they change rapidly. positive net spreads indicate potential profit. negative spreads mean fees exceed the price difference.