This expansion can be combined with all Power Grid maps and available power plant decks. The Stock Companies offers players a completely new game experience. As shareholders, the players want to get control over different stock companies so they can acquire the greatest wealth. Additionally this expansion offers two more variants. In the first variant the players are shareholders who try to get shares of the most successful companies; the companies that supply electricity to the most cities. In the second variant the players control their private stock companies and try to establish them successfully on the electricity market. They sell shares of their own companies to generate more cash and they are able to buy shares of other players