What Are Prediction Markets?
Prediction markets are platforms where you trade on the outcome of real-world events the same way you'd trade a stock or a crypto pair. Instead of one bookmaker setting fixed odds, thousands of participants buy and sell "Yes" and "No" shares, and the price you see is the live consensus probability of that event happening.
How the Pricing Works
Every market on Polymarket and Kalshi resolves to either $1 (if the event happens) or $0 (if it doesn't). The current trading price is therefore a direct probability estimate. A share trading at $0.67 means the market collectively believes there's a 67% chance the event resolves "Yes".
This pricing model is powerful because it's calibrated automatically. Anyone who thinks the real probability is higher than 67% has an incentive to buy and push the price up. Anyone who thinks it's lower will sell or short and push it down. The equilibrium price is the market's best guess of the true odds, updated in real time as new information arrives.
Why Prediction Markets Are Different from Sportsbooks
Three things separate prediction markets from a traditional bookmaker:
- •No house edge baked into the odds. A sportsbook pays you 1.91x for an even-money bet (a 4.5% vig). On Polymarket, an even-money bet pays roughly 1.97x — the only cost is the maker/taker fee and gas, which is usually under 1%.
- •You can sell before resolution. If your "Yes" share rises from $0.40 to $0.75 because new information made the outcome more likely, you can sell now and lock in a 87% gain without waiting weeks or months for resolution.
- •The market is the counter-party, not the house. That means there's no risk of being limited or banned for winning. You're trading against other traders, just like on a stock exchange.
What You Can Trade
The range of markets is broad and grows weekly. The biggest categories today:
- •Politics and elections. Presidential races, primaries, midterms, gubernatorial races, recall elections — both US and international. These get the most volume.
- •Economics and macro. Will the Fed cut rates this quarter? Will inflation exceed 3% by year-end? Recession in 2026? GDP prints?
- •Geopolitics. Conflict resolution, treaties, sanctions, leadership changes, NATO accession.
- •Crypto and tech. Will Bitcoin hit $150k by EOY? Will OpenAI release GPT-6 before December? Will Apple Vision Pro 2 ship?
- •Sports and entertainment. Who wins the World Cup, the Oscars, the next major tournament.
- •Science and health. WHO declarations, drug approvals, mission outcomes.
What Makes a Market "Inefficient"
The whole reason prediction markets are profitable for analytical traders is that they're not perfectly efficient. There are four recurring sources of mispricing you can exploit:
- Information asymmetry. Big news drops at 4am ET. The price hasn't caught up yet. If you have a price alert wired to a news source, you can act before the market adjusts.
- Sentiment overshoot. A single tweet or poll causes a 15-point swing. The crowd overreacts. Mean-reversion strategies work here.
- Favorite-longshot bias. Markets tend to overprice very unlikely events ($0.04 share that should be $0.01) and slightly underprice strong favorites. This is consistent across decades of academic research.
- Thin liquidity. Markets with low volume have wide spreads and stale prices. Sharp traders find these and put in size before the price adjusts.
How Predite Helps
Predite is built specifically to find these inefficiencies. The platform scans every active Polymarket and Kalshi market every 4 hours, runs each through a 3-model AI consensus engine, and surfaces the ones where our estimate diverges meaningfully from the market price. You can sort by edge size, filter by category, set alerts, and (on the Bot plan) automate execution. The next guides in this series — starting with Getting Started on Polymarket — walk you through everything you need to actually trade these signals.