I read a finance forum, and someone posted there asking how to invest their $50 million of Bitcoin, that they were getting out. Apparently they did sell the bitcoin, reserved some of the proceeds for taxes (they hired a CPA), and used the rest to buy an S&P 500 index fund. The messages and followups seemed realistic. They were detailed enough and went on for long enough, that it seemed like more effort and played more straight than someone posting for laughs.
My brother's friend was really into crypto and sold essentially all of his holdings to buy a house outright. I think he kept a small position hoping it would go up even more.
I can't bring myself to invest in such a speculative asset, and it bothers me that the people who profited the most, at least in the first few big runups, were liberterian bros who believed the ideology behind "decentralized finance".