This isn’t always true though. If I buy an equity for 10$ and sell it to you for 11$ who then sells it for 13$ none of us have lost money. Only panic sells an

This isn’t always true though. If I buy an equity for 10$ and sell it to you for 11$ who then sells it for 13$ none of us have lost money. Only panic sells and crashes are zero sum in the way you are imagining.