A key bitcoin trading indicator hit its "narrowest point" in a year. The last time this happened, bitcoin rallied 20% in four months. Cryptocurrency trading and analyst Matthew Hyland said "a swing is almost imminent", while noting that bitcoin's Bollinger Bands, a tool that measures an asset's momentum and volatility within a specific range, reached its "third highest point" on the weekly time frame since its inception in January 2009. He is not the only one who has discovered this new pattern.