The stock of this company, Karuna Therapeutics, rose on 12/22/2023 from around 220$ to 320$ because it is being acquired by a bigger biotech company.
https://finance.yahoo.com/quote/KRTX/
From the volume data on that date, obviously a lot of people sold their stocks for a very nice 45% unexpected profit.
Here's the problem though. In order to get that 45% profit, somebody else had to be willing to buy the stock at 320$. But why would anyone do that? The price obviously will not rise because the company is being acquired, and once acquisition is complete they will get the 320$ back per unit of stock, so no advantage there. There's also the risk that along the way the acquisition falls apart, resulting in declining stock price. Can somebody explain what is going on because purchasing this stock at 320$ looks like financial suicide to me.