I just tripped over a diatribe by a member of the info elite, Shoshana Zubin[Bio NOTE]. It is in that diatribe that I discovered the terminology used in the title of this OP.

On May 6, 2010, at 2:45pm the stock market plunged almost 1,000 points in a matter of seconds. It became known as the Flash Crash, and it spooked a lot of retail investors.