This screen finds stocks whose price has touched the middle Bollinger Band, the 20-day moving average, staying below it. Bollinger Bands(20,2), created by John Bollinger, plot a 20-day simple moving average as the middle band and upper and lower bands two standard deviations away, so the bands widen when volatility rises and narrow when it falls. A rally to the 20-day average in a downtrend is a common selling zone if the line holds.
