Bollinger band don't look perfect for this because it is not an indicator to rely on for proper direction. Some times working with it you can be correct and other time it will fall. Also you can hardly predict when the volatility of the market has ended but you keep being in the market, this is risky to use but if it can be combined with others, then you can manage on it , Bollinger is a lagging type of indicator.
Volatile was based on the coin which you had invested.Most of potential coin will have good volatile.So check the volatile before investing ,or else you can't exchange later.Some people without seeing all this invest their money and cry in the future after the loss.Don't risk in the future,just inverse your money and hold .When the market get into the pump,you can sell your valuable coin.