Stocks slide day after largest one-day plunge

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

The Dow Jones industrials whipsawed again Friday, 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.

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."

The Dow closed down 139.89, or 1.3 percent, at 10,380.43. The Standard & Poor's 500 index fell 17.27, or 1.5 percent, at 1,110.88, while the Nasdaq composite fell 54, or 2.3 percent, to 2,265.64.

Traders were still anxious Friday amid lingering questions about what caused Thursday's sudden drop. Several possibilities were being investigated.

Regulators and Wall Street officials went through millions of trades one by one Friday and canceled thousands as they sought to explain the plunge, undo damage and keep it from happening again.

On Capitol Hill, Sens. Ted Kaufman (D-Del.) and Mark Warner (D-Va.) called for the Securities and Exchange Commission and the Commodity Futures Trading Commission to conduct a thorough study of high-frequency trading and other tools that move markets in milliseconds. And they have asked Senate Banking Committee chairman Christopher Dodd to use the pending overhaul of financial regulations to address Thursday's plunge. The House has scheduled a Tuesday hearing on the matter.