>>510344743 (OP)
In his own words; during his teenage years, after reading and analysing all material he could put his hands on, he stopped trying to predict stock prices and instead started looking at the businesses themselves
>then why didn't he invest in btc mining?
He very possibly did, but a large portion of that is done in china, and it's bad US optics to thrust significant wealth into a supranational competitor that is extorted by the main chinese political body and geopolitical competitor to the remainder of your business interests. I think it's fair to assume he invested heavily in Bank of America, and at his age and status, probably had good reason or information to avoid btc as it wouldn't displace the USD in his (remaining) lifetime