About a year <a href=" http://www.memories-book.co.uk/blog/of-mice-and-men-conflict-essay/#unskilled ">thesis theme blogger</a> They cited as an example a three-month period when a U.S.bank stock index fell 22.84 percent. They said a ProShares ETFmeant to double that index's inverse performance might have beenexpected to gain 45.68 percent, but instead fell 17.3 percent.