Academics label momentum as an “anomaly.” Multiple studies have shown that this anomaly has persisted over long periods of time and across markets (AA). Based on this insight, quite a few quantitative momentum funds sprung up. And since nothing good is ever left alone at Wall Street, a whole bunch of momentum factor ETFs launched to ride the wave during the recent bull market. Currently, there are more than 40 momentum ETFs listed in the US.
So, does this mean that the momentum anomaly has been arbitraged out? After all, with over $12 billion in momentum ETFs alone, shouldn’t the strategy have topped out? We posit that it is unlikely to happen anytime soon. Why? Because investors just can’t help themselves.
Consider the asset under management (AUM) of these momentum ETFs. If, for an ETF, the price is down 10% and its AUM is down 20% over the same period, it means that there has been a net outflow of 10%. If you run this math on all the momentum ETFs traded in the US since October this year, you end up with about $2 billion in outflows in 3 months. That is roughly 11.5% of momentum assets on the 1st of October.
It has been well documented that investors chase performance, often piling into “hot” funds and strategies and exiting on the slight whiff of under-performance. We are seeing this in action on momentum ETFs. And as long as investors are caught in this doom-loop, momentum (and by extension, value, investment and volatility anomalies) will persist.
Also read: Investor education is a waste of time (Aug, 2014)
Code and data are on github.