Wall Street turned in another stunning finish today and extended its unprecedented streak of volatility - this time, to the upside - as investors spent a fractious session again struggling with fears about a recession but giving in to a last-hour wave of buying.
The Dow Jones industrials ended up 400 points, after falling 380 in the opening minutes of the session.
It was clear that investors were reacting in the extreme to any negative economic news, including disappointing data today on industrial production which initially sent stocks skidding.
However traders were also responding to the market's own dynamics, and when there was no late-session plunge, as there was yesterday, buyers piled in before the close.
Analysts expect this extraordinary volatility to continue, and warned that, just as Monday's huge 936-point surge in the Dow was overdone, there was little reason to trust that today's gains would hold.
A rise in shares of Yahoo Inc over renewed speculation that it could cement a deal with one-time suitor Microsoft Corp helped push the technology-laden Nasdaq composite index up more than 5%.
The Dow rose 401.35, or 4.68%, to 8,979.26.
Broader stock indicators also jumped. The Standard & Poor's 500 index rose 38.59, or 4.25%, to 946.43, and the Nasdaq composite index rose 89.38, or 5.49%, to 1,717.71.
Advancing issues outnumbered decliners by about 2 to 1 on the New York Stock Exchange, where volume came to two billion shares.
Stocks spent much of the session seeking a direction after yesterday's steep dive, which took the Dow down 733 points in response to a stream of bad economic news that underscored the likelihood that the country is either in a recession or will be in one - and that the downturn could be severe.
There was no news today to counter those fears - but there were plenty of gyrations in stock prices and the major indexes.
"We're going to continue to see volatility. You're not going to see 50-point ranges, you're going to see two-three-four hundred point ranges," said Woody Dorsey, president of Market Semiotics, a financial forecasting firm in Castleton, Vermont.
Investors initially appeared cheered by a better-than-expected reading from the Labor Department on consumer prices.
The flat reading on September's Consumer Price Index compares with August's 0.1 % decline, which was the first in nearly two years. The core index, which eliminates food and energy prices, rose 0.1%. Economists had been expecting CPI would rise to 0.1% and that core CPI would increase 0.2%.
Meanwhile, a weekly snapshot of the job market showed that first-time claims for unemployment benefits declined last week.
The Labor Department said new claims fell 16,000 last week to a seasonally adjusted level of 461,000 - below the 475,000 that had been anticipated. However, total unemployment remains above the level that economists often associate with recession.
And the Philadelphia Federal Reserve said regional manufacturing conditions weakened in October. The bank's regional index came in at a negative 37.5 compared with a positive 3.8 for September.
That news followed word from the Federal Reserve that production at the nation's factories, mines and utilities plunged 2.8% last month, on top of a 1% drop in August.
While the Fed estimated that disruptions related to hurricanes accounted for about 2.25% of the drop in industrial production, the news was still discouraging for a market which is hypersensitive to anything negative about the economy.
Subodh Kumar, global investment strategist at Toronto-based Subodh Kumar & Associates, said markets are jittery because many investors' expectations about the economy were too rosy heading into the summer and the month-long freeze in the credit markets has dealt the economy another blow, making it harder and more expensive for many businesses and consumers to get loans.
He said the volatility buffeting the markets reflects investors tinkering with their portfolios to match their more sober take on the health of the economy and some investors simply cashing out. That means some vehicles like mutual funds and hedge funds are entering a market already short on buyers and being forced to sell.
Because of investors' great anxiety about the economy, Wall Street is expected to remain extremely volatile, as it has been since last month when the credit markets tightened and stocks plunged.
The gyrations this week have been particularly intense, with the Dow industrials soaring 936 points on Monday and falling 733 yesterday following a weak report on retail sales and a disheartening assessment of the economy from the Federal Reserve.
While the credit markets are performing better than they were last week given several unprecedented actions by governments around the world - including the decision to buy stakes in private banks - they are hardly operating normally.
Treasury bills, considered the safest assets around, remained in demand.
The three-month Treasury bill was yielding 0.49% today, higher than 0.20% yesterday. The yield on the benchmark 10-year Treasury note, which moves opposite its price, fell to 3.97% from 3.98% late yesterday.
Tom Higgins, chief economist at Payden & Rygel Investment Management in Los Angeles, said some professional investors are being forced to turn to the stock market because other markets remain largely paralysed.
"The reason we're seeing volatility in the stock market is because it's the one market that's trading right now. If you have to liquefy your assets and you need access to cash immediately then the market you're going to do it in is the equity market and that's what I think is pushing around the indexes at this point."
Jim Ferrare, senior portfolio manager at Pinnacle Associates, said the changes that will result from government actions around the world to revive the credit markets will take some time to emerge, letting uncertainty linger on Wall Street.
"Volatility is here for a while but also more importantly the change is not an overnight change," he said, referring to the government's steps to restore normal levels of lending.
Indeed, the Wall Street's fear gauge rose to a record level today.
The Chicago Board Options Exchange Volatility Index, known as the VIX, rose to an all-time intraday high of 81.17, its first-ever move over 80. The VIX, which usually trades below 50, tracks options activity for the companies that make up the S&P 500.
Gains by Yahoo helped push the technology sector and the Nasdaq higher. The stock rose after Microsoft chief executive Steve Ballmer raised the possibility of renewing his attempt to buy the internet search company.
In a presentation made at a Florida technology conference, Mr Ballmer said a deal between Microsoft and Yahoo could "still make sense economically".
Microsoft issued a statement saying it has no interest in acquiring Yahoo and that the two companies are not in talks. Earlier attempts to acquire Yahoo fell through.
But it was enough to help Yahoo shares, which early in the session fell to 11.37, their lowest level in five years. The stock rose 1.24, or 10.6%, to 12.99, while Microsoft rose 1.53, or 6.8%, to 24.19.
The Russell 2000 index of smaller companies rose 34.46, or 6.86%, to 536.57.