I know SPXPM options are European style, which can only be exercised on the last day, this Friday. I have a short position as part of a vertical spread. I just want to confirm my understanding, that I can still close out my position any time during the trading day on Friday. Which would mean that when they are talking about exercising only on Friday, what they really mean is that at the close on Friday, all in the money options will automatically settle for the difference between the closing index price and the strike price. In other words, the holder of a long SPXPM option cannot "exercise" it during the day on Friday, thereby assigning me, and I might not know it until after Friday's close. Just trying to avoid a surprise! (as I am sure most of us have had with American style options). Thanks for any answers!