If only you value a peace of paper, it's a joke.
If a few people value it, it's a ponzi scheme
If millions of people do, it's a stock market.

I knew there was something phishy about that thing, but when you realize, that everyone is buying stocks in hope of "growth" based on more people buying in, you might finally understand why it is possible for the stock market to crash or grow way beyond the value of the companies.