Kostolany’s Egg: The Cycle Theory That Predicted Every Market Crash

André Kostolany was a Hungarian-born speculator who spent 75 years on the stock market and became one of Europe’s most influential financial thinkers. He wrote 13 books, was a regular columnist for Germany’s Capital magazine, and famously said that he earned more money sleeping than working. His most enduring contribution to investment theory is a simple diagram that explains how markets move in cycles — and how the majority of investors always get it wrong.

It’s called the Kostolany Egg.