Regulatory Status
The first dimension is regulatory status. Kalshi operates as a CFTC-regulated designated contract market, which provides legal clarity, investor protections, and accountability. Polymarket operates on blockchain infrastructure with less regulatory oversight, offering more flexibility but less legal certainty. PredictIt operates under a CFTC no-action letter with uncertain terms. Each regulatory status implies different risk profiles for your deposited capital.
Liquidity and Market Coverage
A platform with deep liquidity on the events you care about is more useful than one with broad coverage but thin markets. Check the average spread, daily volume, and open interest on the specific contract categories you plan to trade. A platform with $500 million in total volume but only $50,000 in the categories you trade is less useful than a platform with $50 million total but $500,000 in your categories.
Resolution Track Record
How has the platform handled past resolution disputes? Has it resolved contracts in a timely, transparent manner? Has it ever changed resolution criteria after trading began? A platform with a clean resolution history is worth a premium over one with documented disputes or unclear resolution processes.
Fee Structure
Fees vary significantly across platforms and directly affect your expected returns. Polymarket charged no fees through most of 2025. Kalshi uses a variable formula that can be significant near 50-cent prices. PredictIt charges 10% of gross profits plus 5% withdrawal fees. Understanding the fee structure for your specific trading patterns (frequency, contract types, average position size) helps you compare the true cost across platforms.
Technical Infrastructure
Platform stability, uptime, API quality (for automated trading), and execution speed all affect your trading experience and results. A platform that goes down during volatile moments or has unreliable API connectivity can cost you money even if every other dimension is excellent.
Explore these tools on Blockcircle: Prediction Markets Mispricing Engine