Why Most Commodity Futures ETFs are not perfectly replicating their underlying ?

… And the reason why these should not most of times be held more than a few days / weeks. A good example is the USO tracker we recently traded (in /out in less than 10 days ) in the Virtual portfolio.

WSJ – October 9th : “What is Tracking Error in Oil Funds ?”

 

http://www.wsj.com/articles/what-is-tracking-error-in-oil-funds-1476064800