Quote from NoDoji:
retire45 puts it well. I just placed stops on my two short term options trades from late Friday. One ended the day slightly profitable and the other at a still-reasonable loss. Both stocks moved in my favor during after-hours trading. However, if they don't continue to move in my favor, I'm out and placing the stops right now will keep me from analyzing the situation until my losses double. Every day I have to look at some losing trades that I thought (being far back month options) had plenty of time to work in my favor. Now I have nothing to count on but upcoming earnings reports to boost them (and that is not my favorite position to be in).
Josh Lukeman spends the entire first chapter of his must-read book, Market Maker's Edge, on risk control and position management. He just gets right to the point: never risk more than 2% of your capital on any single trade. Period. So when trading a $130K account, losing $2000 per trade is the limit. Neke, how many of your winning trades lost $2000 or more before reversing and making you money? Only two of mine did, and the only reason they reversed was because the market was still hopeful and having periodic rallies.
There are certainly too many of my losing trades that went down 2K and still came back up. I meet that a lot in my contrarian plays. To me it still boils down to reward/risk over the expected time-frame. I have a hard 10% (of account) limit on my stock trades. I know that is way more than most people could handle. If my exposure is right in the first place (and consistent) I do not usually fear the size of the loss. It is when I add on to losing positions most of the terrible things happen. I understand that if you are trading with leverage (say 10:1, 20:1) as in futures, it is inevitable you must have a hard stop loss, so as to be able to play another day.
It is hard to set stop rules on options, given the rate they decline. Moreover I do not like placing market orders on options, because of the slippage. In my opinion, my exposure (percentage of account used) effectively constitutes my maximum stop loss. If I use 10% of account on an option I intend to hold for multiple days, I should be prepared to lose that much. In effect, if I intend to hold overnight, I make sure my exposure is small.

