Prediction markets, in plain English
A prediction market is a place where people trade on whether a future event will happen. The trading itself sets the odds: if more people think YES will win, the YES price rises; if more people think NO will win, the NO price rises.
Outcome tokens
Each market has two sides, YES and NO. Each side is a token that pays out exactly $1 if its side wins and $0 if it doesn't.
You buy a YES or NO token for whatever price the market currently quotes — anywhere from $0.01 up to $0.99. The price always sits between zero and one dollar because that's the maximum payout.
Price = probability
The price is the market's best estimate of the probability of that outcome. A YES price of $0.65 means the market thinks YES will win 65% of the time. A NO price of $0.35 means NO is 35% likely.
YES price + NO price always equals about $1. The tiny gap is the bid-ask spread — what market makers charge to provide liquidity.
Payouts and odds
Your potential payout is your stake divided by the price you pay. A few examples at common prices:
| Price you pay | Implied probability | If you risk $10, you win |
|---|---|---|
| $0.20 | 20% | $40 (4× your stake) |
| $0.40 | 40% | $15 (1.5× your stake) |
| $0.50 | 50% | $10 (1× your stake) |
| $0.60 | 60% | $6.67 (0.67× your stake) |
| $0.80 | 80% | $2.50 (0.25× your stake) |
You can also display odds in the format you're used to — percentages, American moneyline, or decimal — by changing the Odds format in Settings. The math is the same, just the notation differs. See Odds and payouts.
Why this works
Prediction markets aggregate information. People who actually believe a thing put money behind it, and the price moves until the marginal trader is indifferent. That's why prediction markets often beat polls, pundits, and prediction-by-vibes.
What can be a market
Anything with a clear, observable outcome at a known time. 4rho lists markets across sports, elections, crypto, finance, and culture. If a market doesn't yet exist for something you'd trade, the supply usually follows the demand.
Limits
Prediction markets are not stock markets. Two key differences:
- Maximum payout is fixed. A YES token cannot pay more than $1, no matter how excited the market gets.
- Markets resolve and disappear. Once an outcome is final, every share pays $1 or $0 and the market closes. You don't hold a position long-term — you hold it through resolution and then claim.
The next article walks through how to start trading.