Vanguard Shuffles Index Fund Managers

Does it matter who (specifically) is managing your index fund? Or is it just enough to know that Vanguard or, say, BlackRock and its iShares division, is managing the fund? Vanguard seems to take the view that it’s the firm, not the individual manager that counts.

Or at least, that’s the only way I can explain why Vanguard doesn’t alert shareholders to the fact that they changed portfolio managers on nearly 50 funds today. Sure, Vanguard updates the prospectuses—as required—but honestly, how many investors actual read those?