And A Speculator Is...?

Whenever some market goes up or goes down, which happens frequently, the market movement is attributed to speculators. I guess that someone has figured out that there's a difference between speculation and legitimate demand, but I don't get it. Ordinary folks don't get it, either, when they think they're being overcharged for a product or service.

Business involves buying cheap and selling dear, and that sounds speculation, too.

Does that make me anti-business or pro-speculation?