Synthetix is a decentralized synthetic asset issuance protocol built on Ethereum. The protocol allows users to create derivative assets, such as synthetic crypto, forex, equity indices, and commodities on the Ethereum blockchain. Users are able to gain exposure to traditional assets like gold and the Nikkei 225 Index without leaving the blockchain. The SNX token is used as collateral to enable the issuance of these so-called Synths. 


More information here https://synthetix.io/