Some interesting things going on with ProShares ETFs this past week. Every now and then for the last few weeks I have been presenting a list of the ProShares ETFs that have exhibited the strongest performance over the course of the last week or have registered the biggest increase in volume. Since these ETFs are primarily short-term trading vehicles and, as such, can be viewed as indicators of short-term sentiment, looking at the leaders among them can paint a picture of those areas of the market in which short-term investors are currently most interested. Looking back over the course of the previous week, the five ETFs with the biggest gains were: Symbol Fund Name Group Objective Percent Change - Price Percent Change - Avg Volume EFO Ultra MSCI EAFE Ultra 200% of the underlying 12.7% 176.8% EET Ultra MSCI Emerging Markets Ultra 200% of the underlying 11.5% 16.1% XPP Ultra FTSE/Xinhua China 25 Ultra 200% of the underlying 10.9%...