In economic theory, every trade is beneficial for both parties. You have too many cows, but need money and I have money and am hungry - you sell me a cow and we are both better off.

Reality is a little tougher. You and I both run hedge funds. One of us thinks Amazon will go up. The other down. One sells to the other. In a month, only one of us has made money. Exactly what the other missed out on making.

Conversely, I sell shoes. You sell supply chain software. You sell me the software for a million dollars. I save 20 million in costs. I want you to improve the software, so I tell the world about my savings. You sell to ten other customers, and I save another 20 million with improved software. Your investors make money, as do your employees. We grew the pie and we all win.

I don’t know what the world is truly like, but I prefer pretending it’s the latter.