The financial markets are often compared to a casino.
Corporate profits are the key to understanding the investor's edge.
By buying a share of stock gives its holder an ownership claim on that company's earnings. If those earnings go up, then the stock price will usually rise as well. Ownership of a company that has higher earnings should be worth more than ownership of a company that earns less. Not a guarantee by any means, but one where you hold house odds. Maybe you're saying to yourself that just because corporate earnings rise in most years doesn't mean there aren't years in which they fall.