What Are Event Contracts?

What it means

In simple terms, an event contract is a promise: it will pay a fixed amount if a clearly defined event occurs by a stated deadline, and it pays nothing if the event does not occur.

A Yes contract — an event contract that pays $1 if the event happens — is the most common example. A No contract — an event contract that pays $1 if the event does not happen — is the mirror image.

Event contracts are usually binary: either the event happens, or it doesn't. The contract's price tells you how much someone must pay today to hold that promise until resolution.

Why it matters

Here's the basic idea: event contracts turn uncertain future outcomes into simple, tradable propositions. That matters because they:

• Let many people express beliefs about a single question using money as a common unit.
• Produce a market price that aggregates those beliefs into a single number.

The price is not a guarantee; it’s the market’s current consensus about the likelihood of the event, translated into dollars and cents.

How it works

1. A question is created and its resolution rules are defined. The question must be binary and verifiable (for example, "Will candidate X win the November election?").

2. Contracts are created that pay a fixed amount at resolution. For simplicity, many platforms use $1 as the payoff for a winning contract.

3. Buyers and sellers trade those contracts. The market price moves as participants buy or sell based on new information or changing opinions.

4. The event resolves on the deadline or after a verification process. Winning contracts are paid out; losing contracts expire worthless.

The key thing to know is that the contract price is what you pay to buy the promise. If you buy a Yes contract, you own the right to $1 if the event happens. If it doesn’t, you lose the money you paid.

A simple example

helps make this concrete. If a Yes contract costs 62¢ and pays $1 if the event happens, buying one contract costs $0.62. If the event happens, the contract pays $1, so the gain before fees is $0.38. If the event does not happen, the contract expires at $0, so the loss is $0.62.

That single example shows the basic arithmetic: price paid versus $1 payout. The market price also serves as an implied probability: a 62¢ price implies a 62% chance, in the market’s view, that the event will happen.

Common mistakes

Treating price as a certain prediction

A price is an indicator of market consensus, not a certainty. Prices move as new information arrives and can be wrong.

Confusing contract type with outcome

Buying a Yes contract means you profit if the event happens, not if you “want” it to happen. Be clear about which side you are holding.

Overlooking resolution rules

Small wording differences in the question or the resolution process can change whether a contract pays. Always read the event’s definition and dispute rules.

Related concepts

• What Are Prediction Markets?
• What Are Yes/No Contracts?
• How Prediction Market Payouts Work