BTC.sx is a bitcoin trading platform that offers investors the chance to take short and long positions on future bitcoin price movements against the dollar. The platform has brokered over 60,000 trades since the introduction of its leveraged trading service in 2013. It allows positions to be opened with a single bitcoin deposit and does not require a U.S. dollar or cash deposit. BTC.sx is backed by Seedcoin, a seed-stage bitcoin startup virtual incubator.