Many investment managers apply strict portfolio constraints under the guise of risk management best practices. These often include limits in sector over-/under-weightings, geographic concentrations, minimum levels of portfolio holdings and/or market capitalization requirements. The challenge around these types of curbs is that while they are designed to reduce potential return variance, typically in relation to a particular benchmark, they also can considerably constrain excess return potential.
Overly restricting a potential investment universe can work against active managers’ ability to fully exploit research and market mispricing opportunities. To help illustrate this, think of constraints from the perspective of retail consumers.
A consumer who is free to purchase from any retailer without restriction can make more informed choices –and likely better purchases in terms of price, quality and overall value –than consumers who must spread purchases across at least fifty different retailers, restrict purchases from retailers headquartered in certain countries and/or only make purchases from retailers with a minimum of $1billion in annual sales. Applying the same logic to investment management suggests that greater selection choice combined with effective security research can offer a more favorable position to generate excess returns.