# Prediction Market Arbitrage: 12 Opportunities Live Now on Polymarket, Kalshi, and PredictIt (July 11, 2026) _Our cross-venue engine has surfaced 12 live prediction market arbitrage opportunities today, July 11, 2026, offering guaranteed payouts on real-world events._ **Published:** 2026-07-11 **Source:** https://www.startuphub.ai/ai-news/prediction-markets/2026/prediction-market-arbitrage-12-opportunities-live-now-on-polymarket-kalshi-and-predictit-july-11-202 --- 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. Arbitrage ROI by event. Will Alexandria Ocasio-Cort...: ROI % 66.67. French presidential electio...: ROI % 16.28. Who will advance in the Bra...: ROI % 16.28. 2028 Democratic presidentia...: ROI % 5.26. Who will win the 2028 US pr...: ROI % 4.55. 2028 Presidential matchup W...: ROI % 4.49. Cross-venue spreads on July 11, 2026. Source: StartupHub.ai arbitrage engine. **Live arbitrage right now** These update automatically. Tap a leg to open the venue. Not financial advice. - **Will Alexandria Ocasio-Cortez win the 2028 Democratic presidential nomination?**. Arbitrage: 66.7% ROI, locks 40c per $1. Buy YES on [PredictIt](https://www.predictit.org/markets/detail/8153/Who-will-win-the-2028-Democratic-presidential-nomination) at 12c, buy NO on [Kalshi / Robinhood](https://kalshi.com/markets/kxaocsenate) at 48c. - **French presidential election: who will advance? Will Marine Le Pen qualify for the runoff in the 2027 French presidential election?**. Arbitrage: 16.3% ROI, locks 14c per $1. Buy YES on [PredictIt](https://www.predictit.org/markets/detail/8766/Who-will-win-the-next-French-presidential-election) at 65c, buy NO on [Kalshi / Robinhood](https://kalshi.com/markets/kxfrpresadvance) at 21c. - **Who will advance in the Brazilian presidential election? Luiz Inácio Lula da Silva**. Arbitrage: 16.3% ROI, locks 14c per $1. Buy YES on [PredictIt](https://www.predictit.org/markets/detail/8544/Who-will-win-the-2026-Brazilian-presidential-election) at 79c, buy NO on [Kalshi / Robinhood](https://kalshi.com/markets/kxbrpresadvance) at 7c. - **2028 Democratic presidential nominee Will Alexandria Ocasio-Cortez be the Democratic Presidential nominee in 2028?**. Arbitrage: 5.3% ROI, locks 5c per $1. Buy YES on [PredictIt](https://www.predictit.org/markets/detail/8171/Who-will-win-the-2028-US-presidential-election) at 11c, buy NO on [Kalshi / Robinhood](https://kalshi.com/markets/kxpresnomd) at 84c. - **Who will win the 2028 US presidential election?, Gavin Newsom**. Arbitrage: 4.5% ROI, locks 4c per $1. Buy YES on [Polymarket](https://polymarket.com/event/will-gavin-newsom-win-the-2028-us-presidential-election) at 12c, buy NO on [PredictIt](https://www.predictit.org/markets/detail/8171/Who-will-win-the-2028-US-presidential-election) at 84c. - **2028 Presidential matchup Will Josh Shapiro and Marco Rubio be the 2028 Democratic and Republican presidential nominees?**. Arbitrage: 4.5% ROI, locks 4c per $1. Buy YES on [Kalshi / Robinhood](https://kalshi.com/markets/kxpresmatchup) at 2c, buy NO on [PredictIt](https://www.predictit.org/markets/detail/8153/Who-will-win-the-2028-Democratic-presidential-nomination) at 94c. - **2028 Democratic VP nominee Will Josh Shapiro be the nominee for the Vice Presidency for the Democratic party?**. Arbitrage: 4.1% ROI, locks 4c per $1. Buy YES on [Kalshi / Robinhood](https://kalshi.com/markets/kxvpresnomd) at 4c, buy NO on [PredictIt](https://www.predictit.org/markets/detail/8799/Who-will-win-the-2028-Democratic-vice-presidential-nomination) at 92c. - **2028 Presidential matchup Will Pete Buttigieg and Marco Rubio be the 2028 Democratic and Republican presidential nominees?**. Arbitrage: 3.6% ROI, locks 4c per $1. Buy YES on [Kalshi / Robinhood](https://kalshi.com/markets/kxpresmatchup) at 2c, buy NO on [PredictIt](https://www.predictit.org/markets/detail/8153/Who-will-win-the-2028-Democratic-presidential-nomination) at 95c. - **2028 Democratic presidential nominee Will Rahm Emanuel be the Democratic Presidential nominee in 2028?**. Arbitrage: 3.2% ROI, locks 3c per $1. Buy YES on [Polymarket](https://polymarket.com/event/will-rahm-emanuel-win-the-2028-democratic-presidential-nomination-299) at 2c, buy NO on [Kalshi / Robinhood](https://kalshi.com/markets/kxpresnomd) at 95c. - **2028 Democratic presidential nominee Will Mark Kelly be the Democratic Presidential nominee in 2028?**. Arbitrage: 3.1% ROI, locks 3c per $1. Buy YES on [Polymarket](https://polymarket.com/event/will-mark-kelly-win-the-2028-democratic-presidential-nomination-479) at 1c, buy NO on [PredictIt](https://www.predictit.org/markets/detail/8153/Who-will-win-the-2028-Democratic-presidential-nomination) at 96c. [See the full live arbitrage board](https://www.startuphub.ai/arbitrage) or poll the free [JSON API](https://www.startuphub.ai/api/v1/arbitrage). ## 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](https://www.startuphub.ai/arbitrage), 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](https://www.startuphub.ai/api-docs/reference/arbitrage) or open the [live JSON endpoint](https://www.startuphub.ai/api/v1/arbitrage). *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.* --- Original analysis from [startuphub.ai](https://www.startuphub.ai), the #1 AI startup directory. © StartupHub.ai. All rights reserved. You may not republish this article in full without a license. Search engines and AI research tools may crawl and summarize for reference. 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