If R is normally distributed, then 68% of observations fall within +/- 1.00 std. deviations from mean, 90% within +/- 1.65 std. deviations, 95% within +/- 1.96 std. deviations, and 99% within +/- 2.58 std. deviations
Private investment vehicles that manage portfolios of securities and derivative positions using a variety of strategies, often with long and short positions and leverage