To him the mining is fun and games.
Although his is interested in buying a warehouse placing solar on the roof and mining at a much higher level.
He was part owner of a Bank in Lakewood NJ. USA rules state under 14% is all you can own.
He has good money maybe 30 -35 mill.
Yet we are going to Target for cheaper eggs today.
You are correct that his BTC hodl of 5 coins which is 150k out of say 30 million or 0.5% could grow to 5% if btc shot up to 300k.
Still in his case he simply does not need the money.
He was working class guy that did well in stocks and cable ownership. He parleyed it into part owner of a bank. The bank did well he sold it.
He has
real estate
stocks
bonds
metals
cash
BTC
and a few private loans where he finances guys with ideas.
These are the typical wealthy people I met while living in NJ.
maybe a dozen guys and 1 women (she is a widow of my friends partner). all of them were middle class 'norms' that did well.
All of them would stand to gain money they don't need if BTC goes from 30k to 300k. Most of them would hodl it as they don't need the extra wealth.
It seems you've been in good company, from what I understand your friend is doing it for fun and that's great.
Using Solar panels for mining is a good idea but what about weather issues, i hope he has thought about it Or maybe switch to paid electricity while in bad weather.