I know a lot of you guys are upset with the takeover price but my guess is that the Takeda offer was the best offer at the time and IDM decided to take it and leave themselves a 20 business day window for a better offer to come about. They can't solicit another offer but another company can approach IDM and submit an offer. The marketing of Mepact must move forward and since IDM didn't have the capabilities to market the drug, the Takeda offer was the best option.
It is my belief that the stock is trading a couple cents below the tender price because people are playing it as if it is a free call; If a better offer arrives, well then they make the upside and if nothing better comes, well then they tied up their money for a month and got paid a couple of cents.
The appraisal rights and the court action taken by shareholders are two other variables at work but it seems that the top-up option will negate the appraisal rights. The court action might force Takeda to sweeten the deal in order to proceed quickly but that seems like a long shot also. Good luck everyone.