Right, but the distinction is that if I go buy a few thousand shares of DIS today, I'm not handing money to the Disney company, rather I'm handing it to the previous owners of those shares. The total pool of them is fixed, so it's all basically zero sum. At most my purchase might signal (in a microscopic way) to the market that there's demand, and push up the price, which benefits Disney.

It's very different when a privately held company creates new shares to sell, because then the money used to purchase those shares really does go right back to the company.