Polymarket–Kalshi arbitrage opportunities
When the same outcome trades at different prices on Polymarket and Kalshi, you can buy Yes on the cheaper venue and No on the other to lock in a return after fees. LocksBet refreshes stored price snapshots across prediction markets in the background — the opportunities below are fee-adjusted and ranked by guaranteed return.
All Polymarket-Kalshi arbitrage opportunities
Saved snapshots refresh in the background. Verify depth before trading.
How LocksBet finds arbitrage
We refresh order-book price snapshots from Polymarket, Kalshi, and other prediction-market exchanges in the background. Every quoted price is adjusted for that exchange's fee schedule, so the number you see reflects the saved ask after fees — not the advertised ask alone.
Outcomes across exchanges aren't always worded the same way ("Trump wins 2028 GOP nomination" on one venue may be phrased differently on another). We pair markets using both an LLM and a human review queue; only pairs that share the same resolution criteria show up here.
For each matched outcome, we compute the after-fee gap between the cheapest Yes and the cheapest No across the venues. If the combined cost is below $1.00 per share, the difference is a guaranteed return — that's the % shown on each row.
Frequently asked questions
What is prediction-market arbitrage?
Arbitrage exists when the same outcome trades at different prices on two exchanges. Buying Yes on the cheaper venue and No on the other — after fees — locks in a guaranteed return regardless of how the event resolves.
Why do Polymarket and Kalshi show different prices for the same event?
Each exchange has a separate order book, different user bases, and different fee structures. Liquidity gaps, latency between venues, and traders without cross-exchange tooling can leave prices misaligned for minutes or hours.
Are these arbitrage opportunities actually executable?
The prices shown are the latest stored ask-price snapshots, fee-adjusted. Execution depends on order-book depth on each venue and how fast you act — gaps tighten as other traders see them. Always check the current price and available size on each side before placing orders.
How does LocksBet calculate after-fee prices?
We pull each exchange's stated fee schedule and apply it to the displayed ask before computing the gap. Kalshi, Polymarket, and other venues all charge differently; the fee-adjusted price is what you would actually pay per contract.
How often is this updated?
Prices refresh from each exchange in the background. The list shows the latest saved snapshot we have; always verify the current quote and available size on each venue before trading.
Is arbitraging between Polymarket and Kalshi legal?
Kalshi is CFTC-regulated and open to US users. Polymarket's main platform is offshore and access varies by jurisdiction. Trading on both is generally legal where each is accessible, but check each exchange's terms and your local rules.
What does it mean when an outcome is human-confirmed?
Outcomes across exchanges aren't always worded identically. We pair them with an LLM and then have reviewers confirm the match. Opportunities surfaced here have either been individually human-confirmed or AI-validated against the same resolution criteria.
Can I automate this with a bot?
Both Polymarket and Kalshi expose APIs. Many traders run arbitrage bots against them. LocksBet is a live scanner, not an execution tool — we surface the gaps; you decide how to take them.