Prior to that time, all index funds to that point were beta-seeking products that followed the risk and return of a broad market, less a small fee.

FORBES: Investing in Style with Index Funds

The higher the beta, the higher the risk and the higher the expected return.

FORBES: Study Turns Risk/Reward Relationship On Its Head

Portfolio return is a combination of beta, size and value.

FORBES: Any Monkey Can Beat the Market