The whole reason that the investment industry exists is because nobody puts that much money at risk in an index fund. Hedge funds literally exist for that reason. This whole idea that trump would drop his wealth in an index fund is propaganda, its meant to manipulate you about trumps incompetency.
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.
According to actual tax filings, he inherited 600 mil in the year 2000 in the form of NYC real estate, which of left untouched would be north of 10 bil now.
