Navigating the factor zoo around the world: an institutional investor perspective.

The literature on cross-sectional stock return predictability has documented over 450 factors. We take the perspective of an institutional investor and navigate this zoo of factors by focusing on the evidence relevant to the practicalities of factor-based investment strategies. Establishing a sound theoretical rationale is key to identifying "true" factors, and we emphasize the need to recognize data-mining concerns that may cast doubt on the relevance of many factors.