Used in the context of equities, noise signifies stock market activity caused by program trading, dividend payments or other phenomena that is not reflective of overall market sentiment. In this context, it is also known as “market noise.” The concept of noise was formally introduced in a landmark 1986 paper by economist Fischer Black, where he stated that “noise” ought to be distinguished from “information” and that a disproportionate amount of trading occurred on the basis of noise, rather than evidence—Read more at Investopedia. Kenton, Will. “Noise.” 10 May 2018