Price spreads
Arbitrage
Price spreads
Cross-venue price disagreement for the same outcome.
GET
Price spreads
Cross-venue price spreads for paired BTC windows (Kalshi ↔ Polymarket).
Returns a JSON array sorted by absolute
diff descending.
Unlike /arbitrage/current, spreads compare the same outcome side across venues
(e.g. Kalshi YES ask vs Polymarket YES ask). This is not risk-free arbitrage.
For each paired window, the API emits up to two rows: one for YES, one for NO.
diff is side1_price − side2_price where side1 is always Kalshi and side2 is
Polymarket.
Request
Query parameters
Snapshot lookback window in minutes (maps to max staleness).
5m, 15m, 1h, 24h, or 1w.Max spread rows returned (1–100).
Response
YES or NO.Always
Kalshi.Always
Polymarket.Kalshi ask for the side.
Polymarket ask for the side.
side1_price − side2_price.