Here is an interesting comment from Scott Simmon's Fiduciary Focus
column on Morningstar.com.
"Mutual fund companies do not have a fiduciary duty to investors in their mutual funds, but they do have a fiduciary duty to shareholders in those fund companies. That set-up characterizes Fidelity, for example, but it doesn't characterize Vanguard, because Vanguard does have a fiduciary duty to investors in its mutual funds; indeed, the investors in Vanguard funds are the same as the owners of that fund company. (The legendary John Bogle often speaks of the necessity for mutual fund management to be fiduciaries to the investors in their funds.) In the main, though, mutual funds are simply products whose management offers no fiduciary protection to those that invest in them."