Much has been said here about the decay factor of leveraged and inverse ETFs.

For example, buy & hold of IWM would give a negative return YTD of -5.33%. So could a long term bear on January 1, 2011 buying and holding the inverse triple-leveraged TZA expect a YTD return of +15.99%? No, because of high volatility magnifying the decay factor, the actual return YTD on TZA is a dramatic NEGATIVE return of -37.26%. And if you expected a negative return on TNA YTD of only -15.99%, the actual return YTD has been -33.70 %!
But let’s suppose that you were market neutral on January 1, 2011 and, instead of staying in cash, you decided to short BOTH TNA and TZA each with 50% of your account balance, your reward YTD for being market neutral would be a net return of + 35.48% instead of the low interest on your bank account.

This can be a strategy on its own, or an alternative strategy when the robots are in cash like now.
And apparently, the drawdowns are very limited.

Many more details and examples can be found in the following article:
http://falkenblog.blogspot.com/2011/...etf-pairs.html
Billy