Sociedades mutualistas e impuestos

Esto cuenta Matt Levine en su columna de Bloomberg

The Vanguard Group is a mutual fund company whose adviser is owned by the funds, rather than being an independent profit-seeking corporation, so it can charge its funds lower advisory fees than its competitors do. (Disclosure: I am a Vanguard investor.) But the adviser is a taxable corporation, while the funds themselves are not taxable (they just pass through taxes to investors). There is a theory that the adviser should be charging Vanguard higher management fees, to reflect the "arm's length" prices that an independent adviser would charge, rather than the "at-cost" prices that it does in fact charge. Or rather, there is a theory that Vanguard owes taxes on the fees that the adviser should have charged, which would have been profit to the taxable corporation. Crazily, this theory is advocated by a former Vanguard tax lawyer in a purported whistleblower lawsuit seeking billions of dollars in back taxes, of which he wants a cut. Also crazily, there is no obvious flaw in this theory. Like, it seems right? But no one can quite believe it. Anyway here are a blog post and article called "Too Big to Tax? Vanguard and the Arm’s Length Standard," arguing "that the Vanguard 'at cost' pricing is unsustainable under the arm’s length standard, and that the IRS will win in court if it challenges Vanguard’s transfer pricing." It concedes that the IRS and New York attorney general have not gotten involved in the whistleblower case, presumably because no one actually wants to go after Vanguard for undercharging index-fund investors.

¿Tiene obligación la gestora de los fondos (cuyas acciones son de titularidad de los propios fondos) de cobrar por sus servicios a los fondos una comisión “de mercado”? ¿o es legítimo que le cobre a precio de coste?