With that much $$ Mr Trump should have done better than the index if he is that good.

And at least in the UK people and families that want preserve wealth actually run their own funds. There are a number of listed self managed Investment trusts (with low TER) based on preserving family wealth.

RIT Capital Partners is one example 12.6% pa for 30 years its base was Rothschild family money and there are others Much older.