Sell AAPL (cover short puts) - expensive lesson in Greek

Sell AAPL via covering short Nov 170 puts, stock around 190.1. This was one of my worst trades of the year, over a 200% loss on the value of the option, though still a modest loss in dollars.

I am tempted to hold on, but obviously I made a mistake entering the trade. Best to eat the mistake before it eats me. There is always the chance that AAPL finds support here at 190, but an acceleration to the downside could turn a bad trade into an account devastating catastrophe.

This trade was an expensive and painful lesson in theoretical pricing and option Greeks. Implied volatility didn't move lower after the earnings report, like it has in prior quarters. Delta never did kick in on the rally to 206. Theta (time decay) kept showing a big number every day, but never helped much either as volatility picked up. Ouch. This article at option trading pedia has basic definitions of the option greeks (link).

Long GLD