# How does Bloomberg calculate beta?

I tried manually calculating Bloomberg's historical beta based on the historical spread of SPY and equity price data, but I couldn't get the same result. I read somewhere that Bloomberg's default setting bases beta on two years worth of weekly prices. Couldn't get it to work. Would I have to control for something based on the values of px_last?

I used $$\beta = \frac{\mathbf{Cov}_{SPY, Stock}}{\mathbf{Var}_{SPY}}$$.

• It depends on which field you are querying, what your terminal default settings are and what overrides you are using (if any). Oct 22 '20 at 8:50
• Not sure what you mean by "spread". Start by matching the historical volatilities (of total returns, including dividends). Ask Bloomberg Support F1 F1 if you're stuck. Oct 22 '20 at 11:47