This screen finds stocks whose price has just crossed above the middle Bollinger Band, the 20-day moving average. 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. Moving above the 20-day average shows that the short-term trend has turned up, with the upper band as the next target.
