DVW

ProShares' New Short Treasury ETF Arrives Right on Time

"This ETF is meant to track the index at -100% for no longer than a single day."

Ok, but all those reasons you give are LONG TERM trends. Just look at the UNG if you need proof that these derivative ETFs over the long term just plain suck. Personally, I think it's better to trade the ZN futures or short TLT directly.