Investment knowledge required is breadth, not depth as most people think. Why most engineers can’t get rich by investing?
Non-quantitative factors determine success or failure of an investment. People overemphasize the importance of science and numbers in investment, as I mentioned in the book “The Rules of Super Growth Stocks Investing”, section 1-1. Investment is a not a science but an art in the economic field under sociology, which is more related to humanities
Why concentrated investment?
Good companies are rare, two or three will make you very rich. Take Texas Instruments as an example