This Sid Sackson classic has taken many different forms over the years depending on the publisher.
Each player strategically invests in businesses, trying to retain a majority of stock. As the businesses grow with tile placements, they also start merging, giving the majority stockholders of the acquired business sizable bonuses, which can then be used to reinvest into other chains. All of the investors in the acquired company can then cash in their stocks for current value or trade them 2-for-1 for shares of the newer, larger business. The game is a race to acquire the greatest wealth.