1) A real genius can figure out things, including how to get cash. If he can not get cash/investment, he is not genius enough.
2) PhD from top school gives a person good foundation to be a professor or some positions that require PhD. But that does not mean too much in business world. Education is important for any success, but please note education and schooling are different things.
3) PhD making 150K+ in finance is not news.
4) Money is always available for good investment for every single year, regardless the market.
5) If his machine learning is really working, he can train the machine to make money (including initial capital) for him.
6) Real academic research is usually years ahead of its time. Success in business usually needs massive adoption which means right at the time. That is one of reasons that a lot of smart people are not rich.
Overall, all you are talking about is "your friend is kinda smart and plan to stay in research (for some years)". Nothing more, nothing less.