Buy equal amounts. If market goes down: eventually sell the SPXU and use the profits to buy more UPRO (which will eventually go up because the US economy isn't going to 0) If market goes up: you still make money. Over the last 6 months UPRO is up 60% and SPXU is down 46% = net gain of 14% which is probably more than most people made in the last 6 months. Is this technically considered "shorting outside the box" or whatever it's called and therefore illegal? Otherwise it sounds like win/win IB"no wai dood u can't do that weighted ETFs decay u will lose all ur monies!!!" IBallthepeoplewhosayit'sdumbtobebothshortandlongatthesametimeonthesameunderlyingbecause"you'renetzerolesscommissionsDUH!!!"