This article documents a significant time-series momentum effect that is consistent and robust across all examined conventional asset classes from 1969 to 2015. We find that the duration and magnitude of time-series momentum is different in developed and emerging markets, but this is no longer the case when controlling for the currency component. We further demonstrate that time-series momentum captures a significant proportion of international mutual fund performance, but this is predominantly with respect to its long aspect. Finally, the market interventions by central banks in recent years have distorted correlations across assets; this challenges the performance of such portfolios.

We document a systematic seasonal component in the aggregate underperformance of active mutual funds. At the aggregate level, active funds underperform the market and other passive benchmarks only in the first month of a quarter. This intra-quarter performance seasonality holds across fund sizes and investment styles. The pattern is consistent with short-term stock return reversal effects along with aggregate window-dressing and, to a lesser extent, NAV-inflation practices around quarter-ends. We find marginal or no evidence of microstructure biases, fund investor flows, or cash distributions as sources of this seasonality. Our findings highlight new features of the active management underperformance puzzle.