In order to take control of the company the company desiring to acquire another company will propose buying shares at a price that is higher than the market price. Doing so current stockholder will have the financial incentive to sell. This is known as tender offer.
Cash or Stock Mergers
For shareholders, mergers can occur two ways. In a cash exchange, the controlling company will buy the shares at the proposed price, and the shares will disappear from the owner’s portfolio, replaced with the corresponding amount of cash. Other times, companies will announce a stock-for-stock merger, in which holders of shares of the takeover company will have that stock replaced with shares of the new company. Often, the deal is structured as a combination of both methods, with shareholders receiving some cash and some stocks…
Finish reading: What happens to your stock when that company gets sold? – Quora