Polymarket Kalshi Arbitrage

Cross-platform prediction market arbitrage is the practice of exploiting price differences for the same event across two or more prediction market platforms. When Polymarket and Kalshi both list a binary market — say, "Will the Fed cut rates in June 2026?" — and their prices don't align, an arbitrage opportunity exists.

The concept is simple: if you can buy YES on one platform and NO on the other for a combined cost below $1.00, you're guaranteed a profit when the market resolves. One of your positions will pay $1.00 and the other will pay $0.00 — so your guaranteed payout is $1.00, and your profit is the difference between $1.00 and your total cost.

Unlike within-platform arbitrage (where you buy YES and NO in the same market), cross-platform arb introduces additional complexity: different currencies, different fee structures, different settlement timelines, and even different resolution criteria for what appears to be the "same" event. These frictions are what create the price discrepancies — and what make them harder to capture than they appear on paper.

The mechanics of finding Polymarket-Kalshi arbitrage are straightforward in principle. You need to monitor the same event on both platforms and identify when the combined cost of a YES + NO position drops below $1.00.

You don't need to build cross-platform arb infrastructure yourself. Some of the top traders on Polymarket already exploit cross-platform inefficiencies as part of their strategy — buying when Polymarket prices lag behind information reflected on Kalshi or other platforms. With Polycopy, you can follow those traders directly.

Polycopy's Auto Copy feature lets you select a proven trader, set your risk parameters — including a minimum Copy Score threshold — and automatically mirror their qualifying trades. No coding, no API setup, no private key management.

Copy Score is Polycopy's proprietary signal that evaluates how copyable each trade is. It draws from 500K+ wallet histories to score trades based on the trader's historical accuracy, market conditions, category expertise, and timing. By setting a high Copy Score floor, your Auto Copy bot only mirrors the trader's highest-conviction moves — including those informed by cross-platform price analysis that you'd need arb infrastructure to detect on your own.

The result: you get exposure to cross-platform-informed trading alpha without needing accounts on multiple platforms, capital split across currencies, or automated execution infrastructure. Your edge comes from trader selection and signal quality, not from racing HFT firms on execution speed.