This is extremely simplified, and not realistic. One counter to this is markowitz portfolio theory, or "diversification effect".
This is extremely simplified, and not realistic. One counter to this is markowitz portfolio theory, or "diversification effect".
Of course the three short paragraph description of a general principle posted to Hacker News to give a partial answer to someone's 8-word question is simplified. What's the alternative? HN's text box is too short to contain a 4-year business course.