RT Journal Article SR Electronic T1 The Root of Reported Betas JF The Journal of Investing FD Institutional Investor Journals SP 50 OP 53 DO 10.3905/joi.2001.319472 VO 10 IS 3 A1 Reinhold P. Lamb A1 Katheryn Northington YR 2001 UL https://pm-research.com/content/10/3/50.abstract AB While research questions the usefulness of a stock's beta, its widespread availability implies continued use. Whether in a portfolio context or in a capital budgeting scenario, beta and its inputs should be clearly understood in order to enable a more accurate decision. This article provides investors a guide to how beta is calculated on 22 of the most popular websites and resources. The discussion connects research findings about beta's inputs to the data available.