So since you mention Wal-Mart. They have, probably, a better idea of Proctor&Gamble's quarterly sales than anybody but P&G, right? Like Walmart makes some massive double digit percentage of sales of p&g products, and knows about it possibly in real-time. If I was some data analyst at Walmart,I couldn't trade on that, that's misappropriation. But Walmart could potentially spin up a hedge fund and trade (against) their suppliers, until their suppliers threaten to pull product, I think?

Presumably there's a contract between Walmart and p&g that they won't trade in each other's stocks, specifically to prevent this?