Cross-Platform Synthetic Arbitrage (Polymarket-Kalshi)

This bot identifies opportunities where the sum of prices for complementary outcomes across Polymarket and Kalshi deviates from 1.0 (e.g., 'Yes' on Polymarket + 'No' on Kalshi for the same event). When the total is less than 1.0, the bot buys both sides, creating a synthetic position that pays out exactly 1 USDC regardless of outcome, netting risk-free profit if entry cost is below 1.0. The system monitors multiple markets simultaneously, checking for mispricings every 30 seconds. Entry requires a minimum profit of 0.5% after all fees (gas, platform, spread). Exits are automatic upon market resolution or if a better opportunity arises to unwind early. Backtests showed average profits of 0.2-0.5% per arbitrage opportunity, with about 5-10 opportunities per week. Implementation uses Python with a simple CLI interface for monitoring.