Real people don't lose money in that manner. The stock market value of bitcoins or stocks is not a guaranted amount of money that you will receive when selling them, but the amount of money that *others* have received when they sold them. Is what you *would* have received if you had found a buyer as well at that time. But you didn't. You don't have any money before you sell them. Stocks and bitcoins aren't money, they are an expectetion to get money for them, an amount that depends on how much others are willing to pay at the time you are offering them.
Cryptocurrencies are especially dubious. Where's the physical value behind it? There is none at all, not a single cent. There's a value assigned to it because others believe it has that value. It's like taking efforts to build a huge, sophisticated, but useless house of cards and then expecting from others that it has a certain value because it took such a huge effort to produce it. Not the house of card has a value, but the speculation potential of the certificates of ownership.
Likewise, how can a company like Tesla have a stock market value that's a couple times larger than e.g. GM, Ford or Volkswagen which sell a hundred times more cars? It's certainly not about the belief that Tesla will generate loads of profit in the future, but because of the belief that others regard it as having that value... which it actually doesn't have.
As a long-term investment, I would never buy Tesla stocks or bitcoins. Their value is too much dependent on the beliefs of others... and (stolen from George Carlin) think of how stupid the average person is and then realize that half of them are stupider than that.