A bad day in the stock market turned into one of the most terrifying moments in Wall Street history on Thursday with a brief, 1,000-point plunge that recalled the panic of 2008.
It lasted just 16 minutes but left Wall Street experts and ordinary investors alike struggling to come to grips with what had happened — and fearful of where the markets might go from here.
At least part of the sell-off appeared to be linked to trader error, perhaps an incorrect order routed through one of the nation’s exchanges. Many of those trades may be reversed so investors do not lose money on questionable transactions.
But the speed and scale of the plunge — it was the largest intraday decline on record — seemed to feed fears that the financial troubles gripping Europe were at last reaching across the Atlantic. Amid the rout, new signs of stress emerged in the credit markets. European banks seemed to be growing wary of lending to each other, suggesting the debt crisis was entering a more dangerous phase.
Traders and Washington policy makers struggled to keep up as the Dow Jones industrial average fell 1,000 points shortly after 2:30 p.m. and then mostly rebounded in a matter of minutes. For a moment, the sell-off seemed to overwhelm computer and human systems alike, and some traders began referring grimly to the day as “Black Thursday.”
But in the end, Thursday was not as black as it had seemed. After briefly sinking below 10,000, the Dow ended down 347.80, or 3.2 percent, at 10,520.32. The Standard & Poor’s 500-stock index dropped 37.75 points, or 3.24 percent, to close at 1,128.15, and the Nasdaq was down 82.65 points, or 3.44 percent, at 2,319.64.
But up and down Wall Street, and across the nation, many investors were dumbstruck. Experts groped for explanations as blue-chip stocks like Procter & Gamble, Philip Morris and Accenture plunged. At one point, Accenture fell more than 90 percent to a penny. P&G plunged to $39.37 from more than $60 within minutes.
The crisis in Greece, high-speed computer program trading, the debate over regulatory reform in Washington, talk of errant trades — all were pointed to as possible catalysts. But most agreed the plunge would not have been nearly as bad if the markets had not been on edge already over the debt crisis in Europe.
“There is a recognition that the Greek crisis has morphed into not only a European crisis but is going global,” said Mohamed A. El-Erian, the chief executive of Pimco.
On the trading floor of the New York Stock Exchange, traders shouted or watched open-mouthed as the screens lit up with prices plummeting and as phones rang off the hook. “It was almost like ‘The Twilight Zone.’” said Theodore R. Aronson of Aronson, Johnson & Ortiz, a money management firm in Philadelphia. Wall Street managers wandered their trading floors, trying to calm their people and figure out what was going on, and began to notice wild movements in stocks like P&G and Philip Morris.