Читать книгу Competitive Advantage in Investing - Steven Abrahams - Страница 25

Sharpe's powerful simplification of investing into the capital market line and the yardsticks of alpha and beta changed investing. By the end of the 1970s, John Vogel had launched the first passive equity market index fund at Vanguard to enable investors to have an easy way to own the market portfolio. The evaluation of managers by alpha, beta, and other measures had begun.

As research into the implications of Sharpe's framework blossomed, however, a few odd results started turning up. Some of the predictions about asset returns made by CAPM did not seem to fit actual data. This is the essence of any scientific approach: theory may be beautiful, intuitive, or appealing, but it must explain the real world. Theory without confirmation in data risks becoming fiction. Ultimately, one professor at the University of Chicago and one at Dartmouth would make a decades-long project of unveiling considerable flaws in Sharpe's beautiful theory.