There are so many ETFs out there that seem to be constantly decaying towards zero. UNG, VXX, SDS come to mind immediately but there are like 20+ others. Why even bother trading when you can just short these ETFs and double your money almost every year. I also wonder how the SEC can approve such ETFs that have zero chance of making anyone any money if they hold it more than a couple of days. These are the riskiest "assets" on the planet right now. I also wonder if there are hedge funds out there that exclusively short these funds.