Stock market investment decisions of individuals are positively correlated with those of coworkers. Sorting of unobservably similar individuals to the same workplaces is unlikely to explain this pattern, as evidenced by the investment behavior of individuals who move between plants. Purchases made under stronger coworker purchase activity are not associated with higher returns. Moreover, social interaction appears to drive the purchase of within-industry stocks. Overall, we find a strong influence of coworkers on investment choices, but not an influence that improves the quality of investment decisions.

We argue that there is a connection between the interbank market for liquidity and the broader financial markets, which has its basis in demand for liquidity by banks. Tightness in the market for liquidity leads banks to engage in what we term “liquidity pull-back,” which involves selling financial assets either by banks directly or by levered investors. Empirical tests on the stock market are supportive. Tighter interbank markets are associated with relatively more volume in more liquid stocks; selling pressure, especially in more liquid stocks; and transitory negative returns. We control for market-wide uncertainty and in the process also contribute to the literature on portfolio rebalancing. Our general point is that money matters in financial markets.