If you mean crypto coins / Bitcoins, your actual wealth would depend on whether they are top-tier coins or newly minted meme coins.
If you held billions in a new “unproven” coin, you might be wildly rich on paper but you couldn’t turn that wealth into cash if others have not bought into the scheme. Even for top-tier coins, you couldn’t cash in all at once without creating a price crash (known as a “rug-pull”). You would quickly run out of buyers, and your selling pressure would see the market price for what you have drop to near zero.
To cash out without destroying the coin’s value, you would need to use an Over-The-Counter (OTC) desk rather than a public app. and sell privately to large, institutional buyers in small lots over a period of months or years.
Depending on the laws for where you live and the vigilance of their authorities, there are probable implications for proof that you are not money-laundering and requirements to declare any profit for taxation purposes.