NEW YORK — Wall Street capped one of its worst weeks ever with a wild session Friday that saw the Dow Jones industrials gyrate within a 1,000 point range before closing with a relatively mild loss and the Nasdaq composite index actually ending with a modest advance. Investors were still agonizing over frozen credit markets, but seven days of massive losses and the possibility of further government support for the markets tempted some investors late in the session.

The Dow lost 128 points, giving the blue chips an eight-day loss of just under 2,400, or 22.1 percent. The average had its worst week on record in both point and percentage terms. The Standard & Poor's 500 index, the indicator most watched by market professionals, posted its worst weekly run since 1933.

The latest loss also means the Dow is down 40.3 percent since reaching a record high close of 14,164.53 a year ago, on Oct. 9, 2007. The S&P 500, which reached its high of 1,565.15 the same day, is down 42.5 percent.

Investors suffered a paper loss for the day of about $100 billion, as measured by the Dow Jones Wilshire 5000 index. For the week, investors lost $2.4 trillion, and over the past year, the losses have piled up to $8.4 trillion.

But there were signs Friday that some investors believe the market is near a bottom. On Thursday, selling accelerated in the last hour of trading. The Dow was down 221 points at 3 p.m. but closed down 679 points an hour later. On Friday, the Dow was down 468 points at 3 but rocketed 790 points and was up 322 points just after 3:30. It then sold off but closed down only 128.

And the Russell 2000 index, which tracks the movements of smaller company stocks, had a 4.66 percent gain Friday; small-cap stocks are often first on investors' shopping lists when they think a market turnaround is at hand.

"Nobody wants to miss the bottom," said Anton Schutz, president of Mendon Capital Advisors, who said of the Dow's performance, "I view it as a victory that we only finished down 100."

Some investors may have been placing bets ahead of the weekend meeting of officials from the Group of Seven nations, who gathered in Washington to discuss the economic meltdown. One of the potential remedies expected to be reviewed at the meeting is for governments to guarantee lending among banks.

"Everyone is hoping for really good news that can invigorate some buying and break this credit freeze, but your guess is as good as mine as to whether that will happen. I think people are desperate for action," said Jon Biele, head of capital markets at Cowen & Co. "It truly is remarkable to watch what's happening."