Tomorrow Is Another Day: Stocks Overweighted by Active Mutual Funds Predict the Next-Day Market

We show that active mutual fund managers effectively incorporate information about future short-term market movements into security prices. Specifically, when high active-mutual-fund ownership stocks outperform, the market tends to do well the next day, and vice-versa. These effects are modest day by day but are quite large in the aggregate - trading the S&P 500 futures daily based on the strategy delivers an average annual return over 15% with a Sharpe ratio over 0.9. The same findings are also present in other major equity markets all around the world. Various additional tests further suggest that the novel short-term market return predictability results from active mutual fund managers’ collective information advantage about future market movements, as opposed to informed fund flows or temporary price pressure.

Market Predictability Active Mutual Fund Market Efficiency