Single Market Beta: A Preference For Discomfort

Single Market Beta: A Preference For Discomfort by Chris Brightman, Research Affliates.

Yikes is right! Investors continue to underperform the market by a significant margin, as Russ Kinnel of Morningstar reminds us in his 2014 version of “Mind the Gap.”¹ While many theories try to explain this persistent underperformance, I will focus on one: Too many of today’s commentators seem not to notice that our knowledge of investment markets has progressed will beyond the theories of the 1960s.

Today, too many cling to the simple to understand but thoroughly refuted theory of a single market beta. Too many misinterpret today’s ongoing debate about market efficiency as supporting the long abandoned theory that all investors should hold an identical portfolio. Too...