This document discusses systematic and unsystematic risk. It defines systematic risk as risk that arises from market-wide factors and impacts all securities, such as changes in interest rates or the overall economy. Unsystematic risk is specific to a particular security and can be reduced through diversification. It provides examples of different types of systematic risk like interest rate risk and market risk. It also discusses types of unsystematic risk such as business risk, financial risk, and operational risk. The document notes that total risk is the sum of systematic and unsystematic risk. It introduces the Capital Asset Pricing Model for measuring systematic risk through beta and calculates required rates of return.