Is there usually a spike in stock price when acquisition is official?

I notice a spike in X company stock price, when a news of potential negotiation for acquisition from bigger company was released. However let's say if tommorow the official news for the acquisition are released, both of the company parties agreed for the purchase, etc. Is there will be another spike in the stock price of the company that is acquired? Or the shares will be just converted into the new company?

sorry for my English. Not native.
Thanks!