She states, “The information ratio is simply the ratio of the active return of the portfolio divided by the tracking error of its return, with both components measured relative to the performance of the agreed-on benchmark. The active return is the sum of each factor return multiplied by the difference between the portfolio’s sensitivity to that factor and the benchmark’s sensitivity. The tracking error is the standard deviation of active returns over time and can be decomposed into the total factor risk and the active specific risk.”
这个表述里面的active return错在哪里啦？
