The Hidden History Behind the Market's 10% Return

The Hidden History Behind the Market's 10% Return

What a dusty database, a clunky mainframe, and modern AI all have in common. Through the mid-20th century, investing was more folklore than fact. People swapped stories of booms and busts, but no one knew what the stock market actually returned over time. The data existed, but it was scattered, incomplete, and largely ignored. Then, in the 1960s, a radical experiment transformed decades of stock market history into a single, profound insight: Th…