A financial measure of a fund's sensitivity to market movements which measures the relationship between a fund's excess return over Treasury Bills and the excess return of a benchmark index (which, by definition, has ). A fund with a beta of has performed better (or worse if ) than its benchmark index (after deducting the T-bill rate) in up markets and worse (or better if ) in down markets.

# Beta

## See also

Alpha, Beta Distribution, Beta Exponential Function, Beta Function, Beta Integral, Central Beta Function, Dirichlet Beta Function, Incomplete Beta Function,*q*-Beta Function, Regularized Beta Function, Sharpe Ratio

## Related Wolfram sites

http://functions.wolfram.com/GammaBetaErf/Beta/, http://functions.wolfram.com/GammaBetaErf/Beta3/, http://functions.wolfram.com/GammaBetaErf/Beta4/## Explore with Wolfram|Alpha

## Cite this as:

Weisstein, Eric W. "Beta." From *MathWorld*--A
Wolfram Web Resource. https://mathworld.wolfram.com/Beta.html