# The best prediction market apps URL: https://www.market-guy.com/learn/best-prediction-market-apps Updated: 2026-10-15 Four platforms dominate the conversation and they are not competing for the same person. Here's what separates them. ## Key takeaways - Polymarket has the most volume and the widest coverage. Polymarket US is a CFTC-registered, dollar-denominated exchange; the separate global platform is crypto-denominated and closed to US users. - Kalshi is the other CFTC-regulated US exchange, strongest on macro and economic data, and it issues some tax documentation. - PredictIt is held back by position caps and thin liquidity; Manifold uses play money — good for learning the mechanics, not a real probability estimate. - Reading the prices needs no account anywhere, and the venue with the most money on a question usually has the most trustworthy price. ## The four platforms at a glance Four venues dominate the conversation, and they are not competing for the same person. The table sorts out which is which; the sections below explain why each one is the way it is. Key point: If you only take one thing from the table: the venue with the most money on a question usually has the most trustworthy price on it. ## Polymarket The largest by volume and the widest by coverage — politics, sports, crypto, tech, culture and a long tail of everything else. Polymarket US is a CFTC-registered exchange, USD-denominated with full KYC; the separate global platform is crypto-denominated and unavailable to US users. Volume is the reason to care. Deep markets mean tight spreads and prices worth taking seriously, and Polymarket has the deepest on most big questions. - Best for: breadth, liquidity, and the biggest multi-outcome events. - Watch for: state availability, and the thin long tail where the spread bites. ## Kalshi The other CFTC-regulated US exchange, and the one that got there first. Kalshi leans into economics, weather, macro data and increasingly sports, with markets built around scheduled data releases — inflation prints, Fed decisions, jobs numbers. It also issues some tax documentation, which Polymarket's global platform does not, and that alone makes it easier to live with for some people. - Best for: macro, economic data, and anyone who wants a paper trail. - Watch for: thinner volume than Polymarket outside its core categories. ## PredictIt The academic-lineage veteran, focused almost entirely on US politics and long operating under regulatory constraints that cap position sizes and the number of traders per market. Those caps are the whole story: they keep it small, and small means prices can drift from where a deeper market would put them. Historically interesting, but it is no longer where the serious money prices elections. - Best for: US political markets with a long history to look back on. - Watch for: position caps, limited liquidity, and fees on both withdrawals and profits. ## Manifold Play-money by design. Anyone can create a market about anything, which produces enormous variety and a genuinely useful sandbox for learning how pricing works without risking anything. Because there is no real money at stake, the calibration incentive is weaker — prices are directionally interesting and should not be treated as a real probability estimate. - Best for: learning the mechanics, and questions no regulated venue would list. - Watch for: play-money prices are not a substitute for a real market's estimate. ## How to actually choose If you want the most accurate live probability on a big question, go where the volume is — that is usually Polymarket. If you care about macro releases or want tax paperwork, Kalshi. If you want to learn without risk, Manifold. PredictIt is now mostly of historical interest. One thing worth saying plainly: you do not need an account anywhere to use the prices. Reading the odds, comparing them across venues and doing research is free, and it is the part with the best return on effort. Key point: Liquidity beats interface. The platform with the most money on a question usually has the most trustworthy price on it. ## FAQ Q: Which prediction market app is biggest? A: Polymarket, by volume and by breadth of coverage. That matters beyond bragging rights: deeper markets have tighter spreads and prices that better reflect available information. Q: Which ones are legal in the US? A: Polymarket US and Kalshi both operate as CFTC-registered exchanges. PredictIt has long run under specific regulatory constraints. Manifold uses play money. State-level availability still varies for the real-money venues. Q: Do I need crypto? A: Not for the US venues — Polymarket US and Kalshi are USD-denominated with ordinary funding methods. The global Polymarket platform is crypto-denominated, and US users cannot access it. Q: Can I compare prices across platforms? A: Yes, and you should when the same question is listed in more than one place. Market Guy tracks Polymarket and Kalshi side by side so the same question can be compared directly. Q: What are the best apps like Polymarket? A: Kalshi is the closest comparison — a CFTC-regulated US exchange with real money and overlapping coverage, strongest on macro and economic data. PredictIt is the older US-politics venue, constrained by position caps. Manifold is the play-money option if you want the mechanics without the risk. Nothing else currently matches Polymarket on breadth. Q: What is a good PredictIt alternative? A: For US politics with real depth, Polymarket. For anything tied to a scheduled data release, Kalshi. Both lift PredictIt's two binding constraints — the position caps and the thin liquidity that follows from them — while remaining accessible to US traders. Q: Which prediction market platforms exist besides the big two? A: PredictIt and Manifold are the two worth knowing. Beyond them the field thins out quickly into venues with too little volume for their prices to mean much, which is the trait that matters more than the feature list. Q: Is there prediction market software or an aggregator that covers several venues? A: Aggregation is a separate layer from the venues themselves: the platforms run the markets, an aggregator reads across them so the same question can be compared in one place. That is what Market Guy does for Polymarket and Kalshi — and reading the prices needs no account anywhere. ## Sources - [CFTC — Designated Contract Markets (registry)](https://www.cftc.gov/IndustryOversight/IndustryFilings/TradingOrganizations) - [CFTC — Polymarket US Amended Order of Designation](https://www.cftc.gov/media/12806/Polymarket%20US%20Amended%20Order%20of%20Designation/download) - [Polymarket US — live fee schedule](https://docs.polymarket.us/fees) - [Kalshi Help Center — Fees (links the full fee schedule)](https://help.kalshi.com/en/articles/13823805-fees) --- Research tooling for prediction markets. Not financial advice.