Sport Event Cross-Line Arbitrage

This TypeScript bot scans Polymarket sports markets (e.g., winner, spread, over/under) for mispriced lines that create a risk-free profit opportunity. It calculates implied probabilities across all outcomes of an event, and if the sum is below 1 (or below 1 minus trading fees), it places equal-sized bets on all outcomes to lock in a guaranteed profit. Entry is triggered by real-time order book data and historical line movements. Exit is automatic at settlement. The system includes gas estimation, order splitting to reduce slippage, and a paper-trading mode. Backtesting on NFL/MLB markets shows 0.3-1.5% return per arbitrage event.