For newcomers, a prediction market arbitrage lock occurs when you can buy a 'YES' contract on one platform and a 'NO' contract on another for the same event, with the combined cost being less than $1. This guarantees a profit of $1 minus your total investment, regardless of the event's outcome.
As of July 11, 2026, our StartupHub.ai engine has identified 12 such arbitrage opportunities across Polymarket, Kalshi/Robinhood, and PredictIt. These spreads can close rapidly, and potential returns are subject to platform fees, KYC requirements, and withdrawal limits. This information is for educational purposes only and is not financial advice.
Track these live, or poll the free API
The board above refreshes on its own, so this page stays current long after today. The full cross-venue feed lives on the arbitrage board, and every match is also a free JSON API and an MCP tool, so a trading agent can poll live Polymarket, Kalshi and PredictIt arbitrage opportunities and act on them.
curl https://www.startuphub.ai/api/v1/arbitrage?arbs_only=1Read the arbitrage API reference or open the live JSON endpoint.
Informational feed, not financial advice. Live arbitrages are often fleeting, and fees, gas, KYC and withdrawal limits eat into the spread. Verify each market’s resolution rules and costs before trading.