Compute the information ratio from a series of active returns.
| Item | Formula / Rule | Source / Standard |
|---|---|---|
| Information ratio | IR = mean active return / tracking error, excess return per unit of active risk | Grinold & Kahn 2000, Active Portfolio Management, Ch. 4 |
| Tracking error | Tracking error is the standard deviation of active returns, the volatility of deviation from the benchmark | Grinold & Kahn 2000, Active Portfolio Management, Ch. 4 |
| Benchmark use | An IR above 0.5 counts as strong, but it must be compared across managers sharing strategy and benchmark | Grinold & Kahn 2000, Active Portfolio Management, Ch. 4 |