Here's Bloom Energy, a very popular stock that gained its fame because of Nancy Pelosi. Well, that's part of the reason. Bloom Energy also has an interesting business, but take a look at the technical analysis here.
See, when Bloom Energy was moving sideways within a certain range, the Bollinger Band was fairly narrow. It was a little smaller and not very wide . Then, when Bloom Energy experienced a lot of volatility and started trading downwards and facing a lot of negative momentum, that's when the Bollinger Band widened significantly .
It widens noticeably during downturns. That's because more volatility means there are more possibilities for the stock to move further in the future, either downwards or upwards.