The Power Grid: Stock Companies expansion offers players a brand new gaming experience, specifically 3 new ways to play the strategic board game Power Grid or Power Grid Deluxe. The main expansion is The Stock Companies, where players act as shareholders striving to control various stock companies to amass the greatest wealth.

In The Biggest Electricity Distributors, players act as shareholders trying to gain stakes in the most successful companies: those supplying electricity to the most cities.

In the third game variant, The Competition of the Private Companies, players control private equity firms and try to establish themselves in the electricity market. They sell shares of their companies to generate more money, which they can then use to buy shares in their opponents' companies. This also allows them to profit from the success of other players.

The expansion is in English.