This is a bad analysis due to a sampling error. I think the result is biased towards the time frame selected for the study. The market is up over 300% from 1990 so almost any indicator that says buy will look stellar. This indicator need to be evaluated in a flat or down market, how has it done during the last 4 years?
>>indicator that he says has given almost perfect signals for the past 20 years, and it is giving a very clear buy signal now: When that number goes below 10% (i.e., 90% of all stocks are trading below their 10-day moving average), the market is typically much higher three to six months down the road. It was at the same level in August last year, and since 1990, the signal has tripped 15 times. On average, the market is up 4% two weeks later, up 11% three months later and up 24% one year later<<