Herding Behavior among Exchange-Traded Funds

Abstract

ABSTRACTThe author examines whether the trading behavior of exchange-traded funds (ETFs) is biased by any herding effect. Return data of a sample of 66 and 34 large-cap and small-cap ETFs, respectively, are used over the period 2012–2016 to assess whether these funds herd and whether herding is more pronounced during extreme markets, during down markets, and during days with extreme trading activity and volatility. The results show that herding is not the case for ETFs. However, some evidence is obtained on a decreasing return dispersion among ETFs on days with negative market returns. Trading activity seems not to induce herding. On the contrary, the author obtains evidence that shows that the higher the trading volumes are, the higher the return dispersion among ETFs is. When it comes to herding during highly volatile markets, the author finds that return dispersion among ETFs decreases on days with extremely high intraday volatility. However, when assessing the relationship between return dispersion and volatility without focusing on days with extremely high risk, the author obtains strong evidence of a linear relation between the 2 variables. This contradicting finding suggests that the stronger the intraday volatility in the ETF market is, the wider the dispersion in returns among ETFs is.