Platforms
Polymarket vs PredictIt
PredictIt was the original US prediction market. Polymarket is the modern global one. Here is how they differ and which one fits your situation.
PredictIt and Polymarket are often mentioned in the same breath, but they're very different products built for different audiences. PredictIt is a small-stakes academic research platform operated under a CFTC no-action letter. Polymarket is a multi-billion dollar global exchange. The gap is enormous.
Size and breadth
PredictIt caps each market at 5,000 traders and each trader's position at $850 per contract. The result: most markets have low volume, wide spreads, and prices that drift from fair value because no one can size into them.
Polymarket has no such caps. A single market can see $50M+ traded with thousands of active participants. Liquidity is night-and-day better.
Market selection
PredictIt focuses almost entirely on US politics and a handful of long-running political markets (presidential elections, Senate races, control of Congress). Polymarket covers global politics, sports, crypto, AI, geopolitics, business, and culture — orders of magnitude more breadth.
Fees
PredictIt charges a 10% fee on net winnings and a 5% fee on withdrawals. These are steep enough that they materially change the math on every trade. Polymarket's fee structure is far lighter.
Who each platform is for
- PredictIt: US-based political junkies who want a small-stakes outlet. Educational rather than serious trading.
- Polymarket: Anyone outside the US who wants a real prediction market with depth and breadth. Setup guide here.
- Neither: US-based serious traders who want regulated venues — go to Kalshi.