I dont undertstand crypto

I would like to add to this, regular (fiat *eye roll*) currencies are also traded and invested in, by many more people than crypto, the reason their prices arent as volatile is because a lot more people by comparison use them for transaction, therein "cementing" their value. Look at it this way, a dollar can allways buy me a coffe, so its worth a coffe to me, an X-coin on the other hand generally doesn't have as meany real world uses, so the value i see in it is its potential to one day cost way more. A small change in X-coin price is likely to influence that perception, and therein make people either mass buy or mass sell.

Ps: I realize this is a somehwat lacking charecterization and that theres a lot more at play, but it should give a basic idea why something like bitcoing acts so "strange" compared to stocks and fiat currencies