I understand your explanation and it would make sense if other options I have traded acted in a similar way as this. But they haven't. Even when I sold SLW Oct. 26 calls on the last trading day, the premium did not change much, even though the time value had dropped to almost nothing. Other similar options I sold a few days before expiration day without the stock price dropping much and the premium did not move that much. If you look at last week's chart for SLW, you will see that it didn't drop THAT much, and on Friday (the expiration day) the stock price returned almost to where it was trading five days earlier on Monday. I wonder if because Thursday was a holiday and Friday was a half day of trading, along with the fact that this option expired on Friday (not on Saturday as many options do), affected the premium valuation. Of course, I'd love to believe that there was manipulation and I was wronged. As to your reference to options "that have retained an excess of value," that "excess" was lost on Monday and the option premium barely moved with the underlying stock price from late Tuesday to the final day of trading for the week.