We examine the response of investment to peers' stock prices. While the response to average peer-Q is typically positive, the response to prices of peer firms that are more threatening and those of industry leaders is reliably negative. The responses are more strongly negative when the prices...

We show that firms intermediating trade have incentives to overinvest in financial expertise, and that these investments can be destabilizing. Financial expertise in our model improves firms' ability to accurately estimate value when trading a security. It creates adverse selection, which under...