How was Harry Markowitz awarded the Noble Prize in Economics?

Name: Harry Markowitz.
Real Name: Harry Max Markowitz.
Country: United States.
Date of Birth: August 24, 1927.
Died: June 22, 2023.
Education: Ph.B., A.M., and Doctor of Philosophy (Ph.D.) at the University of Chicago.
Subjects Of Study: Portfolio investment.
Popularly Known: Developing Modern Portfolio Theory (MPT).
Noble Prize Year: Nobel Prize for Peace in 1990, for their pioneering work in the theory of financial economics.