The best traders understand how investor and trader psychology can move stocks. If understood and applied correctly, technical analysis is a study of this psychology.The chart of Arm Holdings PLC – ADR ARM is no exception. That's why it's our Stock of the Day.The red line on the chart is called a Bollinger Band. It is two standard deviations above the 20-day moving average. According to statistics and probability theory, 95% of all trading should be within two standard deviations of the mean or average.This ...