Calculating Company Beta

How to Find Beta for a Company
Habib Abdulkarim, Student (MBA), Member
You normally regress using historical movements in prices of the stock. To regress, get historical data on the stock and use y = a + bx to get the vaue for b (where y, the dependent variable is the stock price and b is a proxy for market price - usually a stock index).
See also this video on calculating Beta with Excel.

Calculating the Beta
Deniz Yalcin, Student (MBA), Turkey, Member
@Habib Abdulkarim: When calculating the beta by using CAPM, which of the following would give more consistent and realist results...
We should use the historical data of a t-bill that mimics the Rf rate of course. But which is more proper to put in the regression: the returns of the asset directly OR it's first differences? Thanks..