A Random Walk Down Wall Street (Burton Malkiel)

First published in 1973, now in its 13th edition, Burton Malkiel's masterpiece made the academic case for index investing decades before it was mainstream. His "random walk" theory — that stock prices move unpredictably and no analyst can consistently beat the market — enraged Wall Street and liberated individual investors. The book walks through every investment fad from tulip mania to crypto and shows why a diversified portfolio of low-cost index funds beats them all. It's the reason Vanguard exists. This strategy is cheaper than the average actively managed fund by 1.5% in annual fees, and historical data shows index funds outperform 80% of professional stock pickers over 10-year periods.