# Binary Event Contracts

> Yes/no contracts on any outcome a public data source can confirm, settled in USDso.

When a binary event market resolves, each winning contract pays 1 USDso and each losing contract pays nothing, so a contract's price reads as a probability. If the market is voided instead, every contract refunds 0.5 USDso. Each market trades on its own order book and resolves through the [Somnia Oracle](/data/somnia-oracle), which reads the market's named public data sources.

## How they work

- A market can be built on any outcome a public data source can confirm.
- Rolling interval markets, such as BTC and ETH up/down, open on a schedule.

| | |
| --- | --- |
| Settlement | USDso |
| Resolution | Somnia Oracle |

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