From your case with your friend, I can guess that if he sells, he must sell half the coins. The other half he must have held.
I imagine if the coin he holds is ETH, surely your friend will get more than 25% profit.
For me, your friend has made the best decision.
If he adds ETH coins in the portfolio then it will be very lucky because the increase in ETH is very drastic at the moment, I have allocated part of the investment in ETH because the top coin in recovering assets when other altcoins suffer losses, I hold 40% of the ETH coins in the current portfolio .