While these risk ratios can not always accurately predict future results, alpha and beta help to differentiate between good and bad investments over a given period of time. (cnbc.com)
Discount rate The discount rate is used to calculate how much the expected future income from an investment over a given period of time is worth right now. (daytrading.com)
This is the difference between income and expense over a given period. (investorjunkie.com)