Eugene Fama's 1965 Dissertation

Eugene Fama's 1965 dissertation proposed that stock prices quickly and efficiently incorporate all available information, making it impossible to consistently outperform the market through stock selection or market timing. This idea, known as the Efficient Market Hypothesis, suggests that stock prices always reflect all known data, so investors can't gain extra advantage by analyzing information differently. Essentially, Fama argued that markets are highly effective at processing information, meaning passive investment strategies, like buying and holding a diversified index, are generally as good as or better than trying to pick individual stocks.