Right, in my original post I noted that usually in situations like this, the stock price will pop to around within 5% of the tender offer price. This observable phenomenon is explained logically by the fact that if people believe there is a realistic offer at price X, the market trading price will naturally bid up to price X. I can find a citation for you for the 5% but that is a historically & empirically based figure. I don't really have an explanation for the amount of increase that occurred before Elon's announcement. Given how much he was buying, certainly at least some of that would be attributable to him.

Source: Daily Mail April 15, 2022 06:38 UTC