Each month we track changes to the management teams of actively managed, equity-oriented funds and ETFs. That excludes index funds and most fixed income funds. The index fund exclusion is pretty straightforward: in a passive fund, the managers are interchangeable cogs whose presence or absence is almost always inconsequential to the fund’s performance.

Similarly, most bond fund managers have a very limited ability to add value. Over the past ten years, for instance, the top-performing Core Bond fund in the Lipper universe outperformed its peers by just 1% per year with a virtually identical Sharpe ratio (0.98 for the top returning fund, 0.97 for the average fund). The best global income and flexible income managers outperformed by 3.5 and 2.4%, respectively, which is comparable to the margin between the best large-core equity fund managers and the pack.

This month, we noted just 36 funds with changes in their management teams.

The epochal changes are the departure of John Walthausen from the helm of the funds he launched and long-managed, and of Tad Rivelle, cofounder of MetWest and manager on at least 34 funds available to investors on several continents.

Mr. Rivelle has been on duty for 36 years and Mr. Walthausen for 37. As someone entering his 37^th year as a professional in, admittedly, a different industry, I wish them well as they begin to pen their next chapters.