Quote from C99:
The trade I am referring to is not about trying to capture a roll cost or mgmt fee decay, it is about leveraged ETFs and a mathematical problem with the way they are priced. Many leveraged ETFs, by design and laid out in their prospectus, are supposed to return some multiple (or inverse multiple as the case may be) of the PERCENTAGE return of whatever underlying they are trying to replicate.
Follow the math through:
A simple and extreme example, 2 ETFs, 1 unleveraged and the other 2x levered to provide 2 times the daily percentage return.
Day 1, Index= 100, 1x=100, 2x=100 (you can price the 2x at 200 to start, makes no difference in end result)
Day 2, Index down 15%, Index= 85, 1x=85, 2x=70 (Index and 1x always the same)
Day 3, Index up 20%, Index= (85 * 1.2)=102 2x=(70*1.4)=98
See the problem? And even with realistic inputs, directionless volatility erodes the leveraged ETF price in a very meaningful way, no roll or fees involved.
And yes as you and the article stated there are many risks to the trade, a one-way freight train market, your short getting called at the worst time, etc. I am not advocating it, just saying it's a legit structural pricing problem and some of the people that caught on early made some decent coin.