Siren

SIREN is a distributed protocol for creating, trading, and redeeming fully-collateralized options contracts for any ERC-20 token on Ethereum. Siren uses a fully-collateralized approach to writing options that don’t require any oracles to function.

A single MarketsRegistry contract creates and coordinates individual markets. Once a Market contract is created anyone can interact with it in a permissionless manner. The solvency of a position is ensured at all times by the collateral locked in the smart contract.