Quote from ellevers:
You are correct the auto exercise was .25 and I should have had all my facts before I gave the example; had to look it up but the actually date was june 17 2005 and the actually option was the 280 calls when this happened to me. But my point is still valid for anybody that is interested in if their option will be auto exercised. The last or bid or ask at 3:00 cst has nothing to do if the option will be automatically exercised it is where the closing print happens and the closing prints doesn't mean the last print at 3:00 cst. This also doesn't mean that if you are short an option that you will be automatically exercised for the owner of the option might have other reason for exercising or not exercising. Which is what creates pin risk. People that have conversions and reversals on at the strike where the closing price prints has a decision to make on their long calls or long puts. If someone has the reversal on lets say long 50 10 calls and short 50 10 puts and short 5000 shares and the stock closes at 10 there is no certainty that the person long the 50 puts will exercise. So do you exercise all of your calls? As far as the goog calls and puts go they can very well be at a nickle or at least a nickle at a dime near the close depending on how volatile goog is being. Just last june expiration goog was hovering around the 420 strike with minutes left in the day. You could have easily bought the calls or puts at a nickle at the very least a dime. In the last minute of the day according to time and sales the 420 puts were no bid at a dime. Goog only had a six point range that expiration.
When you're short an option its not the person who bought it from you who directly effects whether or not you get assigned. When an option is exercised the entire pool of accounts who is short that option has the potential to be assigned, its a random selection.
On a stock with a 6 dollar range on expiration day I dont believe that the ATM strike trades for a dime near the close. If you had pin risk you'd be a fool to not close it down for a nickel or a dime and if you were long that strike you'd be a fool to close it for a dime or a nickel.
Dont take this the wrong way I am not calling you a liar I just have a lot of years in the business and on a stock like GOOG or another with that kind of range a dime is too cheap.