when the price reaches or goes above the upper band this indicates increased volatility since bollinger bands adjusts to volatility a widening gap between the upper and lower bands means that the market is experiencing wider price fluctuations which could be due to economic and market news earnings reports and other market events 
for investors using mean reversion strategies the upper band can act as a price target in a ranging market 7 if the price oscillates between the upper and lower bands without a clear trend hitting the upper band can signal to sell or go short because traders expect the price to move back toward the middle band or below in addition when there s a strong uptrend the price might repeatedly touch or stay above the upper band for extended periods this persistence above the upper band might indicate strong buyer enthusiasm and signal that the trend is likely to continue however traders and investors often look to confirm this with other indicators or techniques 8the upper band can also be the site for a breakout a price move that starts at the upper band and continues to push outside of it can signal one especially if there s been an increase in trading volume this indicates that the asset is starting a new trend or accelerating an existing one you could use this signal to trade in the direction of the breakout the lower band of the bollinger bands helps identify oversold conditions it is also a reference line for those using mean reversion strategies or looking for potential reversals if prices stay below this band this could mean the start of a new bearish trend especially if there s a lot of trading volume 