β

Beta

Cost of Capital

Turkish: Beta

Abbreviation: β

Short definition

Beta is the share’s systematic sensitivity to the market portfolio. In CAPM the risk premium is β × ERP. 1.0 moves with the market; leverage lifts beta.

Detailed explanation

Raw beta is noisy in a thin market; peer unlever/relever can be more honest. The window and the index move beta.

Operating leverage also inflates beta. Project beta is not firm beta.

Why it matters for the CFO

It is Ke’s risk channel. A wrong beta quietly moves WACC and EV.

How it is calculated

β = Cov(r_i, r_m) / Var(r_m)

Variables in the formula

  • β: Sensitivity to the market
  • r_m: Market return

How to read it

β 1.2 means 20% more systematic swing than the market. In a thin market 0.4 or 2.0 is often sampling error.

Numerical example

ERP 5%, β 1.20 → beta premium = 6.0 percentage points.

Related calculators

Güven Sayılgan’s writing on this topic

Read these first

What to learn next

  1. Levered Beta
  2. Unlevered Beta
  3. Capital Asset Pricing Model (CAPM)
  4. Cost of Equity
  5. Equity Risk Premium (ERP)

Definitions are educational. They are not investment, credit or tax advice.