Investing with headphones on

'Signal' and 'noise' are electronics-engineering terms that have escaped into wider usage, including that of investment research. Here's how the Wikipedia entry for signal-to-noise ratio introduces the idea: Signal-to-noise ratio (abbreviated SNR) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise ... is sometimes used informally to refer to the ratio of useful information to false or irrelevant data in a conversation or exchange. For example, in online discussion forums and other online communities, off-topic posts and spam are regarded as "noise" that interferes with the "signal" of appropriate discussion. When using electronic devices, you could hear the noise as a hiss behind the music. In investment research, you hear the noise as news, vi