Prediction Market Arbitrage: 9 Opportunities Live Now, Up to 506% ROI

For those new to prediction markets, an arbitrage lock occurs when you can buy a 'YES' contract on one platform and a 'NO' contract for the same real-world event on another platform, with the combined cost being less than $1. This strategy guarantees a payout of $1 regardless of the outcome, locking in a profit.

As of August 14, 2026, StartupHub.ai's cross-venue engine has surfaced 9 such arbitrage opportunities across Polymarket, Kalshi/Robinhood, and PredictIt. These spreads move quickly and can close at any moment, and potential profits can be impacted by fees, KYC requirements, and withdrawal limits.

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=1

Read the arbitrage API reference or open the live JSON endpoint.

Focused guides: Polymarket arbitrage, Kalshi arbitrage, and the arbitrage bot API.

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.