Our cross-venue engine has surfaced 7 prediction market arbitrage opportunities live right now, as of August 25, 2026. An arbitrage lock occurs when buying 'YES' on one market and 'NO' on another for the same real-world event costs less than $1, guaranteeing a payout regardless of the outcome. While these opportunities offer a theoretical guaranteed profit, spreads can close very quickly, and fees, KYC requirements, and withdrawal limits on different platforms will impact actual returns. This information is for educational purposes only and is not financial advice.
These opportunities span Polymarket, Kalshi/Robinhood, and PredictIt, with potential ROIs ranging from 3.1% to over 50%. Any other spreads that opened in the last few hours may have already closed due to rapid market adjustments. We present the most interesting live opportunities below, noting that these are highly time-sensitive.
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.
Focused guides: Polymarket arbitrage, Kalshi arbitrage, and the arbitrage bot API.