Know the old saying, if something looks to good to be true, ...... That may apply here. Certainly for last year what you say is very true. But there are pit falls, so I would be somewhat skeptical. This was discussed on this board a few months back, so here are some post you might like to review.
SVXY did not exist before 10/2011 so it is impossible to go back in history. I did use TNA/TZA history to make an analysis and it showed that it would have worked by year, but the drawdowns by quarter were as high as -16%. I just can not bring myself to trade anything with that size of drawdown regardless of the end result.
But that is just me, if you like what you see, I would say go for it. But I would caution to be careful trading a 1x fund against a 2x fund.
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