How Prediction Markets Work
Prediction markets look simple from the outside. You buy a contract, wait for the event, and get paid if the market resolves your way.
Under the hood, there are several moving parts: market wording, trading structure, liquidity, and resolution rules. If you do not understand those pieces, it is easy to misread what you are buying.
This page gives the broad lifecycle. For a deeper resolution guide, read How Prediction Markets Resolve.
1. Market Creation
The birth of a market requires a clear, unambiguous proposition. A poorly worded question like, "Will the economy crash?" is hard to resolve fairly. A better version names a measurable outcome, a clear source, and a deadline.
The two ironclad rules of market creation:
- The Resolution Source: The creator must designate exactly where the answer will be derived from (e.g., a specific official Federal Reserve press release or the Associated Press election desk).
- The Deadline: An exact date and timezone by which the event must definitively occur to trigger a "Yes" payout.
2. Trading: How Prices Are Set
Once a market is live, traders buy and sell shares. How those traders are matched depends on the platform's underlying architecture. Two common models are order books and automated market makers.
Central Limit Order Books (CLOBs)
Used by regulated platforms like Kalshi and traditional stock exchanges, an Order Book is simply a ledger of everyone who wants to buy or sell at a specific price.
- If you want to buy a "Yes" share instantly for $0.65, there must be another human (or market-making bot) on the other side willing to sell it to you for $0.65.
- If nobody is willing to sell at that price, your order sits on the book until a matching seller arrives.
Automated Market Makers (AMMs)
AMMs are common in crypto systems. Instead of relying only on a human counterparty, an AMM uses a pricing formula and a pool of liquidity.
- Traders deposit capital into a smart contract pool.
- When you buy a "Yes" share, you are not buying it from another person; you are buying it directly from the pool.
- The pricing formula adjusts the quote as demand changes.
3. Resolution and Payouts
After the designated event occurs, or the deadline expires, trading stops and the market enters Resolution. This is the stage where open positions turn into final payouts.
Who decides the winner depends on whether the platform is centralized or decentralized:
- Centralized Resolution: The platform grades the market based on the listed source and its own rulebook.
- Decentralized Resolution: The platform relies on an oracle or other external resolution mechanism because smart contracts cannot read ordinary websites on their own.
Once the truth is established, the platform (or smart contract) instantly distributes funds. Shares corresponding to the correct outcome resolve to $1.00, and all incorrect shares resolve to $0.00.