i posted the following info in another post on this board. It is important to know, because some people say, "hey, the XXX etf is down 20% on the year, but the double inverse etf is only up 5% this year. why isn't the double inverse of XXX up 40%?"
some people just jump into things without knowing what they actually are (I was one of them). i'm a big fan of the double leveraged etfs, but make sure you know what you are involved with. here's the post i mentioned:
the problem with double inverse ETFs like SKF is that they track the DAILY performance, not overall performance. so let's do some math:
UYG is the index that SKF is the double inverse of. let's say they are both at 100 to start, making it easy:
UYG 100
SKF 100
Day 1, UYG goes down 2% so SKF goes up 4%
UYG 98
SKF 104
Day 2, UYG goes up 5%, so SKF goes down 10%
UYG 102.9
SKF 93.6
Day 2, UYG goes down 2.82%, so SKF goes up 5.64%
UYG 100
SKF 98.88
UYG gets back to the same place, SKF trails. The only way SKF is a good LONG TERM hold, would be if UYG NEVER goes up. SKF should be for traders only, as should all inverse ETFs.
If you want to bet against the financials for the long term, short the XLF index. if you want to make some leveraged trades, buy SKF, but i wouldn't hold it for months at a time.
I didn't know the effect of the Daily Performance factor of these ETFs when i was heavy into them earlier this year. It is important to know. People that are smarter than me might be able to figure out some techniques for guaranteed money, like shorting both the long and the short index at the same time.