Firms significantly reduce their investment in response to non-fundamental drops in the stock price of their product-market peers. We argue that this result arises because of managers' limited ability to filter out the noise in stock prices when using them as signals about their investment...

We compare the optimal trading strategy of an informed speculator when he can trade ahead of incoming news (is "fast"), versus when he cannot (is "slow"). We find that speed matters: the fast speculator's trades account for a larger fraction of trading volume, and are more correlated with...