The stock market closed its most tumultuous week ever yesterday with relatively calm trading and little change in prices.

Unmoved by several events that could affect the market in normal times -- comments on the economy by President Reagan Thursday night, favorable reports on inflation and growth, and the announcement that a U.S.-Soviet summit meeting is not in sight -- the Dow Jones industrial average moved up one-third of a point to 1950.76.

For the week, the Dow average of 30 blue-chip stocks closed down 295.98, largely due to Monday's record 508-point plunge.

Analysts said one of the most encouraging signs in yesterday's abbreviated trading -- two hours shorter than normal to give Wall Street firms more time to process orders -- was the decline in volume on the New York Stock Exchange to 245.6 million shares. Some brokers had feared a heavier volume would be compressed into fewer trading hours.

On both Monday and Tuesday, trading exceeded 600 million shares a day; for the week, about 2.3 billion shares changed hands on the Big Board -- more than in all of 1966.

Stock prices displayed little reaction yesterday to reports that the gross national product surged 3.8 percent in the third quarter and consumer prices rose only 0.2 percent last month. Some economists reasoned that given the events of the past few days, the GNP figure had little meaning for the future of the economy. {Story on Page D9.}

Most analysts said the stock market ignored not only the economic indicators but also the president's pledge Thursday night to cut the federal budget deficit.

But Prudential Bache Securities Chairman George Ball said the stock market's flat performance was a positive response to the president.

"It reflects pleasure with what the president said," Ball said. "The European markets were way down {after the president's press conference} and the expectation was that the U.S. market would crater once again. It did not. What the president said and what he did are to be credited for that."

"I would say Wall Street reaction was mixed," said Merrill Lynch chief economist Donald Straszheim. "We were pleased that he did say taxes are on the table. But I think Wall Street was disappointed in the seemingly combative nature of the president's answers to some questions on taxes and the fiscal situation."

Straszheim's colleague at Merrill Lynch, market analyst Walter Murphy, said the market's reaction to the president was muted for other reasons.

"The market is like a person with an exhausted body who needs a good weekend's rest," Murphy said. "Given the volatility of the past week, it is refreshing to have some calm."

Murphy said the calm on Wall Street yesterday followed a return of panic selling on the Tokyo Stock Exchange yesterday, when the Nikkei Index posted its second-biggest one-day loss ever.

One of the reasons for the calm in the U.S. markets, Murphy and others said, was the decision by the Chicago Mercantile Exchange to impose daily price limits on the Standard & Poor's 500 futures index contracts.

The daily limits put a floor and a ceiling on the change in the price of the contracts. Once that floor or ceiling is reached, it should slow the trading of stocks tied to the futures contracts.

Monday's record plunge has been blamed in part on a combination of computer-driven program trading techniques, some of which involved the simultaneous sale of stocks and purchase of the Standard & Poor's 500 futures contracts. By limiting the daily price swings in the S&P 500 futures index -- which represents a basket of 500 stocks -- regulators hope to minimize the volatility caused by the computer-driven trading techniques.

These sophisticated techniques -- known as stock index arbitrage and portfolio insurance -- repeatedly put downward pressure on prices Monday, pushing the stock market into a free fall. Numerous Wall Street executives have compared the way the plunge in futures prices forced declines in the stock market to a case of the "tail wagging the dog."

After Monday's collapse, the New York Stock Exchange sought to minimize the impact of program trading by prohibiting securities firms from using the exchange's automated order system for the trades. There was widespread hope that the Chicago Mercantile Exchange's decision yesterday to set daily price limits on the futures contracts would help prevent a repeat of Monday's crisis, but the Merc said the move may not be permanent.

"It is a temporary thing done to restore investor confidence in the markets," said Andy Yemma, a spokesman for the Chicago Mercantile Exchange.

"I think it is very positive," said Jack Barbanel, senior vice president and director of futures trading at Gruntal & Co. "The thing I am sorry about is that those limits were not imposed earlier." Other futures exchanges also set new daily price limits on financial futures contracts.

The greatest volatility in financial markets yesterday followed rumors of an international coordinated effort to push down the value of the dollar relative to other currencies. The rumors pushed the value of the dollar down and bonds followed. Both recovered somewhat after the rumors were denied.

Fears that the United States was about to embark on a program to drive down the value of the dollar contributed to the stock market collapse early this week.

Nicholas F. Brady, the investment banker from Dillon, Read & Co. appointed by President Reagan to lead a study of the stock price swings, said yesterday he hopes to complete the task within two months. He said he will meet with White House Chief of Staff Howard Baker on Monday to discuss the crisis.

"In analyzing the problem, the underlying world economies are pretty good and they wouldn't call for this kind of dramatic revaluation in common stocks," Brady said. "Is it the interconnectivity of markets? Is it the existence of new financial instruments? Is it technological change?"

During the first half-hour of stock trading yesterday, the Dow industrial average fell 21.55 points. The losses widened to 30 points by 11 a.m., but a rally obliterated nearly all of the losses by noon.

Until the 2 p.m. closing, the Dow traded in a very narrow range in the mid-1900s, before ending at 1950.76. Trading also will end two hours early on Monday and Tuesday to give Wall Street firms time to complete the processing of the unprecedented flow of orders.

Stock transactions must be processed within five days, which means trades executed last Monday will be processed by this Monday. Wall Street executives are hopeful that the problems from the huge order flow will be minimized by the reduced trading hours and employe overtime at most firms this weekend.

While the Dow was up slightly, 1,038 stocks declined, 675 advanced and 302 were unchanged on the NYSE. The average share of stock lost 5 cents in value. The New York Composite Index was down .22 to 139.23. The American Stock Exchange index fell 4.81 to 264.21; the Nasdaq index of over-the-counter stocks was off 7.68 to 328.45.

One of the strongest performers among the blue-chip stocks was Procter & Gamble, which rose 4 1/8 to 82; IBM was up 3/4 to 120 3/4; GE was down 1/2 to 46 5/8; Merrill Lynch fell 5/8 to 26 7/8; and Dow Jones & Co. fell 1/2 to 33. Among local stocks, Marriott was down 1/4 to 31 3/4 while MCI closed at 9, unchanged.

One of the factors that continued to bolster investor confidence in the stock market was the third consecutive day of heavy corporate stock buyback announcements. Dozens of companies, including Atlantic Research Corp. of Alexandria, said the plunge in stock prices made purchases of their own shares an attractive way to use corporate cash. Wall Street officials said one of the reasons companies are moving so aggressively to buy their own stock is that they hope to boost depressed stock prices, which make them vulnerable to takeover attempts.

Meanwhile, the plunge in stock prices this week continued to unravel previously announced buyouts and stock purchase plans. For example, Jardine Strategic Holdings Inc. said it has abandoned plans to buy 20 percent of the securities firm Bear, Stearns & Co. "in light of recent developments."

Even though the financial markets were generally calm yesterday, many on Wall Street and at the Securities and Exchange Commission in Washington were concentrating on the expected operational crunch next week as the huge backlog of trades is processed.

"From the trader's perspective, the market looked calmer today," said SEC Commissioner Joseph Grundfest. "From our perspective, we are dealing with the settlements and backlogs and clearing questions that come from monumental trading of absolutely historical proportions."

There was optimism about processing huge trading volume at Drexel Burnham Lambert Inc. in New York, where Chief Executive Officer Fred Joseph said he was amazed at how well the firm's computer systems were functioning under the enormous strain.

"We are clearing all of our trades," Joseph said. "It is as if nothing happened. We had 900 trades after Monday that were questionable trades, where other firms didn't agree or the price looked wrong. They have cleaned those up so there are three of them left. Our sense is the world is in much better shape than we might have feared."

Joseph said settlement problems could show up next week in London. "London was a mess," he said. "London's operations capabilities this week showed up as a weak link. And Hong Kong, where they shut down the markets, is a whole different kettle of fish."

The repercussions from failed trades next week could be enormous, leaving firms and investors unable to complete transactions and facing unanticipated losses.

In Washington, Dean Witter branch manager Les Silverstone's clients didn't appear to be worrying about operational problems or stock market volatility yesterday.

"The feeling is the panic has subsided and we'll catch back up," Silverstone said. "At the moment, things look quiet and that is a big plus anytime after an explosion."

"You could say the passion is out of the market," said Pru-Bache analyst Larry Wachtell. "You don't get mauled that way and then turn on a dime and get well overnight."

Steven Einhorn, cochairman of investment policy at Goldman, Sachs & Co., said it will take many months to repair the psychological and financial damage from the week's chaotic trading. He described the psychology of investors as "tenuous and fearful."

On a decidedly negative note, Einhorn said the mark remains so weak that a broad-based stock price decline "could be difficult to stop."

At Donaldson, Lufkin & Jenrette, senior trader John Burnett was relieved to see the orderly trading yesterday. But he said investors should beware because "we are in a confused market. It is a spooky environment and there are going to be wild swings. I think you have to treat this market with the utmost of caution."