Measuring Information Diffusion Within Mutual Fund Families

Summary

The article summarizes research on whether information spreads through mutual fund families and how that relates to fund performance. It describes a diffusion measure based on the order in which affiliated funds buy a stock after it first appears in a family portfolio. Faster, more simultaneous purchases imply faster internal diffusion; later purchases during the initiating position’s holding interval imply slower diffusion. The study examines actively managed U.S. equity funds from 2004 to 2012 and tests the relationship using risk-adjusted performance models and controls for fund and family characteristics.

The reported association is positive: families with faster diffusion have better-performing funds, with the effect concentrated in communication across managers with different investment styles. The article also describes placebo and merger-based identification tests, and reports that faster diffusion coincides with more trading, less reliance on public information, and portfolios more distinct from peers. The findings are based on historical mutual fund data and do not establish that the same effects apply to other markets or organizations. The proposed measure infers information flow from observed trades rather than directly observing what managers knew.

Key ideas

• The study infers internal information diffusion from the timing of affiliated funds’ purchases of newly introduced stocks.
• A higher diffusion measure indicates that more family funds buy during the initial information interval.
• The article reports a positive relationship between diffusion speed and risk-adjusted mutual fund performance.
• Communication across managers with different styles is associated with stronger performance effects than communication within one style.
• The authors use placebo and merger-based tests to address confounding and reverse causality.
• The evidence comes from historical U.S. active equity mutual funds and infers information flow indirectly from holdings.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.