>>22103609Since they can't literally buy the VIX, they have to use derivatives to simulate it. Shorter dated VIX derivatives are more sensitive to VIX changes, but have very high error rates, and longer dated derivatives aren't sensitive enough to the VIX because they're trying to predict mean reversion after the move is over. And market makers often manipulate the derivatives during rollovers to screw people. Then add on high levels of leverage. The details vary widely depending on how a specific fund is set up, and I'm not familiar with SG's, but the long term result can end up like UVXY.
