Set of several stocks having different degree of risk exposure to different types of economic factors such as changes in interest rates, inflation, and/or oil prices. The stocks are chosen in such a way that the portfolio as a whole is strongly affected by one factor (has a beta close to 1) but is weakly affected by other factors (has a beta close to 0). These portfolios are constructed based on the history and projected behavior of the influencing factors, and usually include both long and short trading positions.