Cross-Market Prediction Market Arbitrage

How It Works The scanner monitors identical or near-identical event markets across three platforms — Kalshi, Polymarket, and PredictIt — and flags cases where the same outcome is priced differently. A trader simultaneously buys the underpriced outcome on one platform and sells (or buys the opposing outcome) on another, locking in a spread.

Entry Conditions Entry is triggered when the price for the same underlying event diverges across platforms by more than the combined transaction costs (spreads, fees, withdrawal delays). The scanner operates continuously to catch transient mispricings.

Exit Conditions Positions resolve naturally at market expiry, or can be unwound if prices converge before resolution. Given platform withdrawal friction, most positions are likely held to resolution.

Verified Results No verified results are provided. The repo has zero stars and one fork, suggesting early-stage or personal-use tooling.

Implementation Notes & Risks The primary structural risk is capital lock-up: funds on Kalshi, Polymarket, and PredictIt cannot be instantly moved, so true simultaneous arbitrage requires pre-deployed capital on all three platforms. PredictIt's $850 per-contract position limit further constrains scalability. Regulatory differences between platforms add operational risk. Execution timing differences can turn arbitrage into directional risk.