NEW YORK — The stock market's wild ride may not be over yet.

The Dow Jones industrials whipsawed again yesterday, a day after their largest one-day plunge. The average was down as much as 279 points in the morning, went briefly into the black around lunchtime, then ended with a loss of 139.

Not quite as terrifying as the brief 1,000-point plunge the day before, but still extraordinarily volatile. It's normal for markets to trade erratically a day after such a disruptive move, but analysts are divided over whether stocks are in the process of finding a bottom or whether too many investors are too spooked to get back in.

"It's a pile of uncertainty ... We don't have any more clarity than we did yesterday," said Art Hogan, chief market analyst at Jefferies & Co. in Boston. "We're going to have investors who are less inclined to be in this marketplace until we get some clarity."

Traders were still anxious amid lingering questions about what caused Thursday's sudden drop. Several possibilities were being investigated but as of late yesterday no clear explanation had emerged.