When a group of investors with dispersed private information jointly invest in a risky project, how should they divide up the project payoff? A typical common stock contract rewards investors in proportion to their initial investment, but is it really optimal for harnessing all investors’ “wisdom of the crowd”? By showing that a simple profit-sharing contract with decentralized decision making could first best coordinate individuals’ investment choices, this paper studies as a general contracting problem the role of profit sharing in harnessing the crowd wisdom, and discusses implications for the security design of investment crowdfunding.