A private risk is uncorrelated with the market. The risk of rain tomorrow and the risk of an accident at 5:00 p.m. today on Interstate 95 are private risks (unique risks). Equally unique is the risk of the failure of a dam or the risk of obtaining unfavorable data in a clinical experiment on a particular drug of a pharmaceutical company. These types of risks are not related to what is happening in the general economy. All the risks mentioned will have the same chance of happening whether the economy is in recession or growing rapidly.