Z is a standardized measure of the distance between the rank sum of the negative group and its expected value. The expected rank sum is 45.5, half the sum of all ranks. The standard deviation is 14.31. The negative group rank sum equals 31, so the Z statistic is (31 - 45.5) / 14.31, or -1.013.

- The two-tailed asymptotic significance estimates the probability of obtaining a Z statistic that is as extreme or more extreme in absolute value as the one displayed, if there truly is no difference between the group ranks. In this case, the probabilities for both tests are above any reasonable cutoff.

From this analysis, the investment analyst can breathe a sigh of relief. His technology stock holdings did not underperform on a daily basis in the years 2000 and 2001, compared to the median daily performance of all other stocks on the S&P 500 over the same period.