Beta measures the change in returns in a fund compared to the change in returns of a diversified stock index (representing the market) over the same period. The diversified stock index, by definition, has a Beta of 1. Funds whose Beta is more than 1 means that its NAV (price) changes more than the market and hence is riskier than the market. When the market rises, NAV of these funds rise a lot more and when the market falls, the NAV of these funds falls a lot more. Beta less than 1 is indicative of a fund that is less risky than the market.