While systematic risk is both unpredictable and impossible to completely avoid, investors can manage it by ensuring that their portfolios include a variety of asset classes, such as fixed income, cash, and real estate, each of which will react differently to an event that affects the overall market. An increase in interest rates, for example, will make some new-issue bonds more valuable, while causing some company stocks to decrease value. So, making sure that a portfolio incorporates ample income-generating securities will mitigate the loss of value in some equities.