Constantinos Antoniou is Associate Professor of Finance and Behavioural Science at University of Warwick Business School; Avanidhar Subrahmanyam is Distinguished Professor of Finance, Goldyne and Irwin Hearsh Chair in Money and Banking at University of California Los Angeles Anderson School of Management; and Onur Tosun is Assistant Professor of Finance at University of Warwick Business School. This post is based on their recent paper.
Recent work has highlighted that exchange traded funds (ETFs) contribute to a decrease in the pricing efficiency of the underlying securities (Ben-David, Franzoni and Moussawi, 2017). This is because, due to their high liquidity, ETFs attract high-frequency traders. Moreover, since ETFs and the underlying assets are bound by no arbitrage conditions, volatility in ETFs caused by high-frequency trading can propagate to the underlying assets, as arbitrageurs trade to exploit violations of the law of one price. As a result, the stock prices of companies with high ETF ownership are more noisy.
Corporate managers rely on stock prices for information, since stock prices aggregate information about the future prospects of their companies from a large pool of outside investors, and some of this information is not known to management. This reliance on the stock price leads to the well-established positive relationship between stock prices and corporate investment, which indicates that the managers of companies with higher stock prices (which are deemed by the market to have good growth opportunities) invest more heavily.