Quote from demoship:
You think these ETFs have JUST calls or JUST puts?
Did I
say that?? No I didn't, did I? But, nice try.
What they do have is swaps that are somewhat like synthetic shorts, but have asymmetric return characteristics relative to a true short position. Whereas a short position can lose more than its position size, the swaps that ProShares short funds enter into can only go to zero, due to a regulatory regime laid down by the SEC. That means they have an embedded option. For the Ultra funds, obviously that embedded option becomes quite significant.
I'll give you the punchline:
And those positions are close to 0 theta.
Close to, but not exactly, zero. Which makes them options.
A few years ago, just for the heck of it, I calculated the time decay on some ProShares funds based on historical price data. It turned out to be several percent per year, above and beyond the management fees of course - I don't remember the exact numbers.
For SKF with the sky-high volatilites involved, the time decay is likely to be much higher, though piggie2000's estimate of 25-40% seems out of the ballpark to me. Just off the top of my head, I would guess more like 8 - 12%. Nonetheless, there is absolutely no question that time decay represents a significant factor in the returns of these funds.
Your assertion that leveraged ETFs aren't options is dead wrong -- they have significant embedded options and hence time decay like any option.
Martin