USO has such a non linear relationship with crude. Intractable..it has the same problems as vxx to vix futures.... You are speculating on price and a changing roll cost/yield that is another factor of speculation as well... I'd love to see this factor quantified into a measurable risk to get a sense of what might need to be tolerated... I as well would like a longer term long position with a call option... I've mainly looked at otm calls on the actual futures contracts