The Price of Street Friends: Social Networks, Informed Trading, and Shareholder Costs

Recent studies suggest the transfer of privileged information via social ties but do not explicitly examine the cost of these ties to shareholders. We document a significant positive relation between stock transaction costs and a company’s social ties to the investment community. Social ties based on education and leisure activities, stronger ties, and ties to individuals responsible for trading have greater effects. Using investment connection deaths as natural experiments, we document that exogenous severance of ties reduces trading costs and trading activities by connected parties. Our evidence illustrates an important and previously undocumented consequence of social ties.