I am clueless when it comes to ETF's. Would appreciate some help. I understand the basic difference in FAS vs. FAZ, however why would one buy one vs the other? Who primarily buys these instruments? Are they used to hedge large financial stock positions? I looked at the holdings of FAS. Most of the portfolio is in cash instruments. How are they replicating a 3X? There is something about rebalancing each day but I don't follow the mechanics of this. If you were going to do options on either FAS vs FAZ is there a difference in the market for options on either of these instruments, i.e., if you were going to play options which would you do? I am new to these markets. The about has probably been explained somewhere a thousand times.