This paper analyzes the behavior of moving average technical trading rules applied to over 100 years
of the Dow Jones Industrial Index. It is found that the differences between conditional means during buy
and sell periods has changed dramatically over the previous 10 years relative to the previous 90 years
of data, but differences in conditional variances have not changed much over the entire sample. Further
robustness checks indicate that similar results could be obtained with simple momentum based strategies.
The analysis is performed on the actual Dow series, but these techniques could be useful in derivative
markets where better estimates of conditional means and variances would be useful information