Its fairly interesting when you dig into it.. According to @dantheman "Steem Dollars are convertible to STEEM at the current price of STEEM. This means that all Steem Dollars could be converted to “common stock” in less than one week which in turn would instantly adjust the market capitalization of Steem."[https://steemit.com/steem/@dantheman/how-to-calculate-the-market-capitalization-of-steem]