Updated from 4:14 p.m. EDT

Stocks in New York wrapped up their fourth consecutive positive session on Friday, recording 9%-10% gains for the week and fueling some optimism on Wall Street.

The Dow Jones Industrial Average rose 53.92 points, or 0.8%, to 7223.98, while the S&P 500 added 5.81 points, or 0.8%, to 756.55. The Nasdaq also ended Friday's session with gains, tacking on 5.4, or 0.4%, to 1431.50.

General Motors ( GM) and Merck ( MRK) led the Dow, adding 24.8% and 12.7, respectively.

For the week, the Dow rose 9%, the S&P 500 rose 10.7%, and the Nasdaq added 10.6%.

Optimism has crept in as stocks locked consecutive days of gains. "I think that was the first time I've heard traders and analysts say that it could be the bottom, but we have to be very careful because nothing has fundamentally changed," says Anu Sharma managing director of the market intelligence desk at Nasdaq OMX.

"One concern is that it was on light volume, an indication that people's minds haven't necessarily changed, and people aren't putting money back into equities," he says.

Moreover, says Sharma, we're roughly two-and-a-half weeks from the close of the quarter, and after an abysmal start, fund managers might see a small rally as an opportunity to take some quick profits and minimize the damage. Prior to the run-up, the major indices were down nearly 20% for the quarter.

Stocks overseas had an optimistic session today, too, namely Japan's Nikkei rose 5%, and Hong Kong's Hang Seng moved up 4.4%. Japan's prime minister is calling for a new stimulus package, and Chinese Premier Wen Jiabao, after expressing some concern over U.S. Treasuries, said the Chinese government is prepared to take further steps to reinvigorate their economy as well.

The U.S. census bureau said Friday that the U.S. trade deficit was narrowed to $36 billion in January, from $39.9 billion in December, and compared to expectations for $38 billion.

Undoubtedly helping stoke the week's rally, Citigroup ( C) and JPMorgan ( JPM) said earlier in the week that they have been profitable thus far in 2009. Those stocks were up 6.6% and 2.4% Friday.

Investors were also happy to hear that General Motors isn't going to need $2 billion of the rescue money it originally asked the U.S. government for. That Dow component was rising 24% early Friday.

Plus, a downgrade actually worked in General Electric's ( GE) favor Thursday because it wasn't as bad as expected and included a stable short-term outlook. The stock was up just 0.5% on Friday.

On Friday, Fitch Ratings downgraded Berkshire Hathaway's triple-A issuer default rating and senior unsecured debt ratings by one notch, in light of the volatile market.

Meanwhile, BMO Capital reduced its estimates for Mac-Maker Apple ( AAPL). Shares were down 0.4% at $95.93.

In commodities, oil fell $1.47 to settle at $46.25 a barrel, while gold added $6.10 to $930.10 an ounce.

Stocks abroad were largely higher. The FTSE in London was up 1.1%, while the DAX in Frankfurt edged down just 0.07%.

Longer-dated Treasuries were falling. The 10-year note was losing 6/32 to yield 2.9%, and the 30-year was off by 22/32, yielding 3.7%. The dollar was weaker vs. yen, euro and pound.