DUG and USO

I know they are tracking different stocks, and one is 2X reverse and another is 1X. However, it makes no sense to me that both DUG and USO are down big since Oct, 2008. Oil is down big since 2008,10, should not DUG be up really big?

Can anyone explain?"

DIG and DUG both are down big since 2008/10, why?

 

hint: it's all based on percentages.

 

http://www.elitetrader.com/vb/showthread.php?s=&threadid=149747