From signal to selection

Summary: A factor score tells you one thing about a stock. It says nothing about the governance behind it, the balance sheet underneath it, or whether the trend it's riding is built on something real. That gap is where pure factor indices and rule-based smart beta funds begin to diverge.

Summary: A factor score tells you one thing about a stock. It says nothing about the governance behind it, the balance sheet underneath it, or whether the trend it's riding is built on something real. That gap is where pure factor indices and rule-based smart beta funds begin to diverge. Factor investing has brought discipline to a field long swayed by persuasive stories. Momentum can be measured through price behaviour while value can be assessed against fundamentals. Both can be tested against history. A stock no longer enters a portfolio merely because a manager has a compelling narrative. Yet a factor score captures only one trait. It may reward a strong trend despite weak governance or treat a damaged business as merely cheap. This is where pure factor indices and rule-based active smart beta funds begin to part company. The virtue of a narrow mandate Pure factor indices offer transparent rules at relatively low cost. They give investors direct exposure to factors like momentum or value without relying on continuing judgement. An index must admit any stock that meets its rules, even when the resulting portfolio looks uncomfortable. A fragile company can rank highly after a sharp rally. A cheap stock may be mispriced, though it may