Modern finance is based upon investors' receiving greater expected returns from undertaking greater risks. However, literature has well documented entrepreneurs undertake larger risks than their returns could justify. In this book, a new theory is developed to explain the above entrepreneurial risk/return puzzle. In my framework, I argue that entrepreneurs or people investing in private equity usually place a higher value on personally held information or assets under personal control as compared to general public information and these beliefs lead them to assess lower risk regarding such assets. Correspondingly, they require lower returns as compensation and they tilt their investments toward such assets. A heterogeneous CAPM model is thus derived to investigates how the heterogeneity in the risk perception influences investors' portfolio choices. The model also provides explanations for other financial puzzles including size premium puzzle, investors' local bias/home bias puzzle, investor's under- diversification puzzle, and different entrepreneurial behavior patterns in different market regimes, etc.