Definition
Cross-market arbitrage is the general category of strategies that profit from price discrepancies for identical or near-identical instruments traded on separate markets. The key requirement is that the two instruments must be economically equivalent — so that holding both at once is risk-free (or near risk-free), and the profit is captured from the mispricing alone.
Forms of cross-market arbitrage
- Exchange arbitrage: The same stock listed on multiple exchanges at different prices (e.g., dual-listed equities)
- Crypto arbitrage: Bitcoin priced differently on Binance vs Coinbase
- Prediction market arbitrage: The same binary event on Polymarket vs Kalshi at different prices
- Sports betting arbitrage (surebetting): Different bookmakers offering complementary odds on the same event
What makes prediction market cross-arbitrage distinctive
Unlike stock or crypto arbitrage (where you're trading the same asset), prediction market arbitrage involves two complementary positions — YES and NO — that together pay exactly $1.00. This eliminates directional risk entirely: it doesn't matter which way the event resolves. The profit is guaranteed at settlement.
The matching challenge
In stock or crypto arbitrage, the instrument is identical by definition (same ticker, same asset). In prediction markets, the same event may have completely different titles, slightly different resolution dates, and different oracle sources on each platform. AI-based semantic matching is required to reliably identify true cross-market pairs at scale.
Barriers to entry
Cross-market arbitrage in prediction markets is accessible to retail traders but requires:
- Accounts on both Polymarket and Kalshi
- Capital split between both platforms
- Automation for both detection and execution (manual is too slow)
- Accurate event matching (false matches create losses, not profits)
Arbitrage Agent handles all four automatically. Join the waitlist for early access.