I think most traders have qualms about using a system that goes against the prevailing trend.
It seems anti-intuitive, and does not instil a sense of confidence. It is more natural that they prefer a system which goes with the trend.
Based on charts, I wonder if you agree with my near-term significant support levels for the big boys in QQQQ:
AAPL .... 148, now trading at 156
GOOG .... 555, now at 636
RIMM .... 85, now at 103
MSFT .... 31, now at 33.50
Based on economy:
AAPL .... great products but they are expensive in a recession
GOOG .... advertising always drops way off in a recession
RIMM .... same as AAPL
MSFT .... been asleep for years; let sleeping dogs lie
For all of above .... they've all been great -- take profits while you can.