open.assets are IOUs backed by OpenLedger, they are not backed by BTS collateral. The coins called "Smartcoins" are the blockchain-level assets backed by BTS collateral (e.g. BitUSD, BitCNY, etc). Despite this, there are several advantages to trading open.assets compared to trading on a centralized exchange:
- the market itself is decentralized and is therefore not subject to potential manipulation and front-running by an exchange owner
- you can trade between IOUs and Smartcoins offered by different companies and individuals (anyone can create a new market between their own coin type and coins offered by others)