INVESTORS have been clamoring for months for a bit of good news. They got a load of it yesterday.

The Dow Jones industrials shot up 240 points to a two-week high of 7,170, bringing its gains over the past three days to 622 points, or 9.5 percent. It was the index's biggest three-day jump since last November.

Surprisingly positive signals this week from companies across all industries, particularly banks, have made traders think twice about continuing to drive stocks lower. It's too soon to tell whether this week's upturn is the beginning of a bull market or simply a temporary rally within a bear market, but either way there has been a pronounced change in Wall Street's tone.

"How all this turned around in a week, I don't know," said Scott Bleier, president of CreateCapital Advisors. "But it's certainly a better outlook than how it looked two weeks ago."

The rally got an extra dose of adrenaline yesterday after an accounting board told Congress it may recommend an easing in financial reporting rules of tough-to-sell assets - a change that banks say would help their bottom lines. Upheaval in the banking industry has been dogging the market since 2007, and hope that banks might finally get relief in how they value their bad assets spurred a flurry of buying on Wall Street.

"We might find that the banks are not as bad, or not bad at all, if these assets are marked differently," said Doreen Mogavero, president of the New York floor brokerage Mogavero, Lee & Co.

Better-than-expected retail sales figures also helped stocks, as did positive news from four Dow companies: Bank of America Corp., General Electric Co., General Motors Corp., and Pfizer Inc.

GE's credit rating was cut by less than expected, GM said it will not need a US$2 billion loan it previously requested from the government, and Pfizer reported a successful cancer drug trial. Bank of America's CEO told reporters his bank was profitable in January and February. Citigroup Inc. triggered this week's rally Tuesday with similar remarks.

No one is calling the end to the selling on Wall Street. The economic picture is too uncertain, and much of this week's rally has been driven by technical factors. One of those factors is traders' inclination to buy stock to cover "short" bets, or bets that a stock will fall.

But it's been the most reassuring week in months for the stock market. The Dow Jones Wilshire 5000 index, which reflects nearly all stocks traded in America, has jumped 11.2 percent over the past three sessions. That's a paper gain of US$900 billion.

"There's a lot of money on the sidelines, and a lot of people who've been waiting for the turn to come," Mogavero said. "I think that probably, people will want to get some of their money in the market."

The Dow rose 239.66, or 3.5 percent, to 7,170.06. The Standard & Poor's 500 index climbed 29.38, or 4.1 percent, to 750.74. The Nasdaq composite index gained 54.46, or 4 percent, to 1,426.10.

The Russell 2000 index of smaller companies rose 23.82, or 6.5 percent, to 390.12.

After a modest decline Monday and three days of buying, the Dow is up 8.2 percent so far for the week. The S&P 500 index is up 9.9 percent and the Nasdaq is up 10.2 percent. Before this week's rebound, the Dow and S&P had tumbled to their lowest levels since 1997 and 1996, respectively.

Advancing stocks outnumbered decliners by more than 10 to 1 on the New York Stock Exchange yesterday, where consolidated volume came to 7.2 billion shares, up from 7.1 billion shares Wednesday.

Not all of yesterday's data was positive. The Commerce Department said retail sales dipped by a modest 0.1 percent in February, but the Labor Department reported that first time claims for unemployment benefits rose last week to 654,000 from 639,000 the week before, more than analysts had expected.

Investors are also aware that much of this week's rebound can be attributed to covering short positions. Traders have been covering short bets by buying stocks, especially after the Securities and Exchange Commission said it was considering reinstating the "Uptick Rule." The rule, eliminated in 2007, aimed at curbing short-selling by only allowing it when a stock edged higher.

Investors grew more optimistic yesterday about bank stocks after the chairman of the independent Financial Accounting Standards Board told the House Financial Services subcommittee on capital markets that the board "could have the guidance in three weeks" on so-called "mark-to-market" accounting.

Frozen demand in the credit markets has sharply lowered the value of assets having anything to do with real estate or consumer credit - even though most of the loans themselves are still getting paid off. Those lower asset values have translated into huge losses for banks.

Citigroup rose 8.4 percent, Bank of America rose 19 percent, Wells Fargo & Co. rose 17 percent, and JPMorgan Chase & Co. rose 14 percent.

GM rose 17.2 percent to US$2.18 after its chief financial officer said it would not need its federal loan for March.

GE rose nearly 13 percent to US$9.57 after Standard & Poor's downgraded the conglomerate by one notch from "AAA" due to troubles in GE's lending arm.

Meanwhile, pharmaceutical stocks soared yesterday on more acquisition news and a positive drug trial at Pfizer Inc.

Pfizer said it ended a successful trial of its cancer drug Sutent early after data showed the drug met its goal of slowing the progression of pancreatic cancer. Shares of Pfizer, a Dow component, rose nearly 10 percent to US$14.02.

Switzerland's Roche Holding AG agreed to buy the rest of Genentech Inc. for US$46.8 billion, while Gilead Sciences Inc. agreed to buy CV Therapeutics Inc. for US$1.4 billion. Earlier this week, drugmakers Merck and Schering-Plough agreed to merge in a US$41 billion deal.

Government bond prices rose, driving the yield on the 10-year Treasury note down to 2.86 percent from 2.91 percent late Wednesday. The dollar strengthened against other major currencies, gold prices gained, and crude oil surged US$4.70 to US$47.03 a barrel on the New York Mercantile Exchange.

Overseas markets were mixed. Britain's FTSE 100 rose 0.5 percent, Germany's DAX index rose 1.1 percent, and France's CAC-40 rose 0.8 percent. Japan's Nikkei stock average dropped 2.4 percent, while Hong Kong's Hang Seng index rose 0.6 percent.