Loss: Why Crashes, Timing & Valuations Matter (Chapter 3 of 5)

The first two articles in this series were about behavior. How to think like an investor instead of a speculator, and how to keep your own wiring and your own training from robbing you. This one is about arithmetic. Cold, unemotional, undefeated arithmetic. Underneath every good decision and every bad one sits a layer of math that does not care how you feel, and Wall Street would very much prefer you never do it in your head.