"Modern portfolio theory gives a rigorous mathematical justification for the time honored investment maxim that diversification is a sensible strategy for individuals who wish to reduce their risks. Invented in the 1950s by Harry Markowitz in this book, the theory provides a firm foundation for the intuition that you should not put all your eggs in one basket and shows ... Read moreinvestors how to combine securities to minimize risk." Butron G Malkiel, author of "A Random Walk Down Wall Street" "In every field of study it is possible to look back and identify a person or event that caused a major change in the direction or development of the field. In investments it is clear that the seminal work by Harry Markowitz on portfolio theory changed the field more than any other single event." Frank K. Reilly, University of Notre Dame, Indiana Show Less