I measure once a month the decay of major leveraged ETFs. It may be useful for anyone using leveraged ETFs for investing, trading, or hedging.
Where does the decay come from?
Most of the time, a leveraged ETF does worse than the underlying asset leveraged by the same factor. This relative decay has several reasons: beta-slippage, roll yield, tracking errors, and management fees. Only the latter is predictable. Roll yield may be prominent for commodity ETFs (leveraged or not), but beta-slippage is usually the main reason of decay. However, it doesn't always result in decay.