The Avalanche
People often use the "deer in headlights" phenomenon as an analogy for tumultuous markets.
That's probably a misappropriation.
After all, a deer that's caught in headlights is anything but erratic. It's frozen. Unable to react or, more colloquially, unable to get the fuck out of the way.
Here's David C. Yancy, a deer biologist with the Kentucky Department of Fish and Wildlife Resources to explain why this happens:
Deer are crepuscular. Their activity peaks within an hour or so on either side