Beta

There are 5 principal risk measures of unit trust performance. They are alpha, beta, r-squared, Standard Deviation and sharpe ratio.

Beta measures a fund's sensitivity to movements in the benchmark index.

Before you read Beta, make sure R-squared should be at least 0.85. Otherwise, beta doesn't reflect the fund's sensitivity to the benchmark index.

a fund with a beta of 1.5 tend to gain 1.5% for every 1% rise  the market and lose 1.5% for every 1% decline in the market.

Thus, if beta is 1, then it imitates the benchmark index completely.