It occurred to me that the oft-discussed "volatility decay" that many here are so opposed to with leveraged ETFs could easily be offset, with daily management of course, using a simple algorithm. You just invert what the underlying ETF is doing when it rebalances.
- Start with $1000 in UPRO for $3000 exposure to VFINX.
- VFINX drops 10%, equity is now $700 with $2700 exposure.
- UPRO sells $600 and "unborrows" it, to bring exposure back to 3x = $2100.
- Thus, you
buy $300 of VFINX outside the adventure, half the amount the fund sold, since the principal is half the borrowed amount.
- VFIN goes up 10/9 = 1.11..% bringing it back to where it started.
- Equity is now $700 + $2100*1/9 = $933, exposure is $2333.
- UPRO borrows $467 and buys, to bring exposure back to 3x = $2800.
- Thus, you
sell $233 of VFINX outside the adventure, half of $467.
- You now own $933.33 in UPRO and $300 - $233.33 = $66.67 in VFINX. So you've successfully countered the volatility decay.
I wonder if folks who are vehemently opposed to volatility decay would consider running this algorithm *without* the UPRO component, for some sweet volatility rejuvenation?

It would work in a flat market. It amounts to swing trading on daily fluctuations - buying at the end of down days and selling at the end of up days. That's probably one of the very first bad ideas every beginner investor has to be disabused of though.
Anyway, just thought this was a fun thought experiment, there can certainly be advantages of avoiding daily releveraging - it lets one time the market when setting leverage if so inclined (eww), and having leverage decline over time without touching the portfolio may be useful.