Cashing out 7+ figure portfolios?

Apologies if this has been answered before, I did my best to search but didn’t come up with much. Disclosure, I don’t have this money (I wish I did) but I have a theoretical question. For all the over night Shiba millionaire and billionaires, are they able to cash out? I understand there are fees and taxes but if someone’s $2000 investment was worth $100,000,000 could they just transfer it to another coin and cash it? Could they cash directly from Shiba and would it be worth the value that shows in their portfolio? I have a high school acquaintance on Facebook who had $3000 invested and he’s now flaunting it all over social media calling himself a billionaire showing screenshots of his wallet. Is he really? Thanks for any info.