No major US investment firm has used social technologies like discussion boards to build an open investor community. But social media adoption is galloping forward, especially among online traders and young investors. In fact, the client base at most major investment firms is more engaged with social media than US online adults on average. Investment firms that ignore this groundswell risk losing investor attention — and, over time, assets — to firms that do figure out how to incorporate social media into their prospect and client strategies. To get moving, we recommend that firms start small to gain confidence and establish sensible corporate policies even in the absence of guidance from regulators.