Buy low sell high.
Unless you are Warren Buffet, your "ownership" of a company is a effectively a meaningless drop in the ocean. And they can dilute your shares even further whenever they want. Us retail investors are just betting on swings in share prices, either short or long term. We bet on a company increasing market share, or releasing a better product, or benefiting from a supply crunch, regulation, etc, just like a gambler would bet on a football team beating the expected spread.
There was a famous quote "The stock market is just a casino without the free cocktails"