Hi. I bought some 100 CME 230 puts on expiration day for .10 or $1,000 total with the misguided principle that puts are limited to your initial investment, but always sell before expiration anyway. In the last seconds of the trading day the stock plunged $5 and at the end of the trading day the puts ended in the money by 1.38, but it happened too late to sell. My broker, Ameritrade, has a statement that says I need to notify it by 4:30 EST if something is not to be exercised if it is in the money by more than .01. I did call Ameritrade on Friday but after 4:30. During after hours trading the share price and strike price quickly evened at 230. Anyway, Saturday comes,they exercise, my $1k turns into $2.3MM, Geinther talks that Sunday and the stock gaps up $7 a share. I lose everything and then some. I've since learned lots. The OCC warning (I really did read the book before all of this) is like saying smoking isn't the most healthy activity as opposed to smoking can kill you. Diatribe aside, my remaining question is: If an option is no longer in the money on Friday? Why exercise it on Saturday? Alternatively, why can't options be traded after hours if the underlying security still can be? Even if I could buy and sell on Saturday at the same time I wouldn't have made any money...just some trading fees for Ameritrade.