Both are mutual funds. UOPIX strives for twice the performance of the NDX. USPIX strives for twice the inverse performance of the NDX. <img src=http://stockcharts.com/def/servlet/SharpChartv05.ServletDriver?chart=uopix,uu[w,a]daclyyay[p][vc60]> <img src=http://stockcharts.com/def/servlet/SharpChartv05.ServletDriver?chart=uspix,uu[w,a]daclyyay[p][vc60]>