Back when I was fantasizing about what I'd do if I won the lottery, I looked into family offices a bit and concluded that there's basically no point as far as the investing advice goes. It's still likely a good idea for some of the ultra-wealthy for estate, tax, and philanthropic purposes, but on the investment side? The standard passive indexing approach used by middle class individuals scales in a cost-effective manner to the <i>billions</i> of dollars of assets. And as a bonus, you don't need to stake your fortune on a trust-based relationship. Instead, you get to base things off of institutions and audits - Vanguard isn't going to take the money you shoved into VTSAX and embezzle it through investing in their distant cousin's "company", even if it is a billion dollars.