Multiplayer stock market game with real money

Twitch launched Stock Stream, which is a multiplayer stock market game that uses $50,000 of real money for trading. During each five-minute round, players vote for stocks they want to buy or sell, and a player earns points if the stock goes up during the five-minute period. The game runs at the open and close of the market, and the game ends if the value decreases to $25,000. [via Waxy]