PredictMarketCap is a unified data layer for prediction markets. We track every actively traded market across Polymarket, Kalshi, Limitless, and Hyperliquid — over 200,000 contracts in total — and present them in one place: rankings, cross-platform price comparison, arbitrage detection, whale trades, and original analysis.
Most prediction-market data lives behind a single platform's lens. Polymarket has its API; Kalshi has another. Each tells you the local price for a contract — but not whether that price is competitive, whether the same event trades cheaper somewhere else, or how the global field is pricing it. PredictMarketCap closes that gap by ingesting live data from every major platform and normalizing it into a single view.
The same real-world event — say, the 2028 Republican nomination — trades on multiple platforms with different contract structures, outcome names, and resolution rules. Our pipeline uses LLM-based matching to identify when two contracts are pricing the same underlying question, then surfaces them side-by-side. You see whether Polymarket and Kalshi agree, where they diverge, and how the spread is moving.
Read the methodologyWhen two platforms price the same event differently, there's a fee-adjusted profit hiding in the spread. Our arbitrage scanner runs every five minutes against the full canonical event graph and surfaces opportunities with annualized returns, fee modeling baked in, and direct links to execute on each platform.
Open the arbitrage scannerOn-chain trade data from Polymarket and Kalshi is filtered, sized, and presented as a feed of meaningful trades — five-figure positions and up. Every trade links to the wallet that placed it, so you can follow the smartest money or watch a single trader's portfolio evolve.
See the whale trackerEvery page on PredictMarketCap is free to read with no signup required. We do not paywall data, gate API access behind a registration form, or sell user data. If you find a useful page, share it; if you write about prediction markets, cite us.
We are not affiliated with Polymarket, Kalshi, Limitless, or any other platform. PredictMarketCap is a data and journalism layer that sits on top of the public APIs each platform publishes. We do not facilitate trading; trade links route directly to the originating platform.
Our analysis articles are written from the data up: every claim is grounded in a specific number, a specific market, or a specific transaction. We publish hour-by-hour timelines, hourly probability curves, and named-trader breakdowns rather than opinion pieces.
Articles include the data window covered, the sources queried, and links to the underlying markets. When markets resolve, we update outcome callouts. We do not publish forecasts of our own — the prediction markets are the forecast; our job is to report what they say.
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