How Can a Strategy Everyone Knows About Still Work?
by Clifford Asness, Ph. D. AQR Capital Management, Inc.
Some assert that once a strategy is “discovered” it can’t work anymore. Others, often implicitly, assume the future will look as wonderful as the past. Perhaps not surprisingly, we stake out a middle ground. We’re going to argue that certain well-known classic strategies that have worked over the long term will continue to work going forward, though perhaps not at the same level and with different risks than in the past. We will focus on classic “factor”-type strategies. Our favorites won’t shock anyone. They are things like value, momentum, carry and quality/defensive. Of these, we’ll use value investing as a common example throughout this discussion.
We don’t consider these classic strategies to be “alpha” in the traditional sense. However, there can be better or worse versions of them, and creating new, better versions is certainly a form of alpha (this can lead to great semantic battles). Still, to be real alpha something has to be known to only a modest number of people/organizations (one being optimal). By this definition, classic strategies defined in well-known ways don’t fit. But, presumably sometime in the past, when they were much less well-known, they were indeed at least closer to “alpha” in all senses of the word. This brings us to the title question — now that they are “classics” and known to many, why should they still work?
First, of course, let me say that all else being equal, everyone would prefer that only they knew about these strategies! It is hard to argue that widespread knowledge of them is a good thing for those few who knew about them before. We think in the past we (the “we” is those collectively doing many of these systematically 20-25 years ago) were in the position of knowing about these strategies and using them when they weren’t widely known. We believe that many strategies make a journey from alpha to a middle ground. This middle ground is a place where they are known, still work — though perhaps not at the same level as in the past — and eventually fall under a set of overlapping labels like alternative risk premia, style premia, priced factors, exotic beta, and, of course, smart beta. When you realize this journey has occurred, there are two important things you must do. First, decide if you really believe the strategies will work going forward. That is, are they now really “premia” or are they gone? Importantly, if you believe they will keep working, be cognizant of how they might act differently now that they are more widely known, both from return and risk perspectives. Secondly, make sure these strategies are available for a fee consistent with something being known and not with the higher fee appropriate if you believe something is true, unique alpha.