Prediction Market Arbitrage: 5 Live Opportunities on August 20, 2026

StartupHub.ai's proprietary cross-venue engine has surfaced 6 prediction market arbitrage opportunities as of August 20, 2026. These opportunities involve the same real-world event being priced on two different venues, such as Polymarket, Kalshi/Robinhood, or PredictIt, where buying a 'YES' on one venue and a 'NO' on the other costs less than $1 combined.

An arbitrage lock occurs when you can simultaneously buy 'YES' on one market and 'NO' on another for the same event, with the total cost being less than $1, guaranteeing a profit regardless of the outcome. Five of these spreads are live right now, while one was seen earlier today and may have already closed. Spreads can move extremely fast, and fees, KYC requirements, and withdrawal limits can impact actual returns.

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.