Who Clears the Market When Passive Investors Trade?
研究发现公司是指数基金买入的主要卖方，几乎一对一地提供股票，主要通过非一级市场发行（如员工股权薪酬）满足被动需求，表明被动投资在过去二十年通过促进股权发行系统性地向公司提供了资本。
Abstract We find that firms are the primary sellers who clear the market for index fund buying, providing shares at a nearly one-for-one rate. Most demand-side institutions trade in the same direction as index funds rather than accommodating passive demand. We use two instruments for index fund demand and show that firms causally respond to exogenous passive demand, with prices serving as the coordinating mechanism. Firms satisfy passive demand mostly through nonprimary market issuance, for example, through employee stock-based compensation. Our results suggest that passive investing has systematically supplied capital to firms by enabling equity issuance over the last two decades.