shorting both faz and fas at the same time is pure lunacy. jprad, i dont know why you keep countering this, just fade away from this thread dude.
Theory:
Faz at 100
Fas at 100
For the next 20 days, each day the underlying raises 1%.
Day1:
Faz: 100-3(3%)=97
Fas: 100+3(3%)=103
Day2:
Faz: 97-2.91(3%)
Fas: 103+3.09(3%)
etc...
A sane person would already see the problem, the two triple etf mimics the DAILY PERCENT movement. So as the price goes lower in the faz example, the ACTUAL DECREASING DOLLAR amount becomes smaller, and on the opposite as the price of fas goes up, the ACTUAL INCREASING DOLLAR amount becomes bigger.
And if you are shorting both, you will lose more money from fas than gained from faz, this loss will become bigger and bigger over time.
Real world: Look at Nov 10, 2008 to Nov 21, 2008.
On 2008/11/10 open
Fas: ~52
Faz: ~63
On 2008/11/21
Fas(LOD): ~11
Faz(HOD): ~200
So if you shorted both on 11/10. You would lost ~135 on faz, and gained 41 on fas. For a net loss of ~90 a share, which will sure to trigger a margin call.
Note: I agree with the fact that those triple etf is losing value over time due to the way they are structured, but shorting both at the same time is just plain retarded.
It's not rocket science fellas.