By what percentage did you increase your initial investment? I'm just curious about trading options in general. Would be interesting to learn how holding onto your postition for that time period paid off.

I shorted the equity directly.

The main costs are:

    - Transaction and Margin costs (those are generally 1 cent per share per side, roughly .06%)
    - Borrow costs (For that trade it was 30% annualized.  I held it for 6 days so its .7%)

So the cost to the trade was .76%. The gross return (since you calculate returns relative to the starting point) is (31.5 - 27) / 31.6 = 14.28% and the net return is 13.53%

Note that I didnt short as much as I could have -- obviously the return would be higher if I borrowed extra money to short.

Interesting. +1 for sharing actual numbers as that helps the learning process along quite a bit imo.