The great Bollinger Bands are one of the first things we must learn when analyzing time series. This is because of their sound statistical reasoning, their wide adoption across market participants, and their success when deployed in trading strategies. We can also see other variations that resemble the...

(Image credit: NASA/ Q.D. Wang) Gaze up at the Sagittarius constellation, and you are looking at the center of the galaxy. It may not look like much to the naked eye (especially if a bunch of is blocking your view), but to the world's sharpest and telescopes, the archer hides a chaotic collage of black holes , exploding stars, magnetic fields and inexplicable bubbles of gas.