I do think it breaks down in practice for the goal of deciding which given trade/bet is gambling. I worked for market makers. Their theoretical job is to provi

I do think it breaks down in practice for the goal of deciding which given trade/bet is gambling. I worked for market makers. Their theoretical job is to provide liquidity. They are required to always give a price. So if the theoretical cereal maker wanted to buy a wheat future to reduce risk, the market maker has to offer to sell them one. Then the theoretical farmer comes along later and the market maker buys a matching future and they're back to even. That by your definition is not gambling. But the fraction of trades that can be justified as actually helping hedge a real risk is very small. Some people trading are pure speculators, pure gamblers. But some of the non-gambler participants will trade in ways that are effectively gambling as well. I think it's effectively impossible to always tell on a trade by trade basis which ones are gambling. We could say it's all related to hedging, as the law does, but I think that's in practice ridiculous. It's a business filled with degenerate gamblers. So I return to my point that even though there's no bright line, it's still worth muddling though and finding some practical guidelines.