The blocks nearby, once filled with investment houses, are now home to apartments and luxury goods stores like Tiffany and Hermès.  The decline in activity at the exchange’s headquarters at 11 Wall Street is palpable. Tourists no longer queue up by the hundreds to survey the floor from the visitors’ gallery or watch the ceremonial ringing of the opening and closing bells. Excluded for security reasons since 9/11, they can only wander by the building that has long symbolized the heart of American commerce.  If they could get inside, they would see that a once-vital organ has been reduced to a reliable backdrop for financial shows on cable. Camera crews flocked there again on Tuesday to capture the reaction to the lowering of interest rates by the Federal Reserve.  But even on its busiest days, the trading floor is a sideshow compared with the center-ring attraction it was several years ago. Most of the action in shares listed on the New York Stock Exchange happens electronically, between the computers of traders at brokerage houses, mutual fund companies and home offices in spare bedrooms.  The instantaneous execution of trades those computers allow has diminished the value of much of what the humans on the floor used to do. For the last several months, the floor has accounted for less than half of the trading in the 2,700 stocks listed on the exchange. Three years ago, that share was about 80 percent.  “The floor as we knew it is dead,” said James J. Angel, an associate professor of finance at Georgetown University. “The old days when Billy would trade with Vinny and swap information about orders so that they could get a better price for their customer are gone.”  At the core of the old system was a small army of specialists, who staffed trading posts and were responsible for maintaining orderly markets in particular stocks. The specialists stand ready to buy or sell stocks with their own money, if necessary. But lately, that need arises less and less often.  This summer, specialists were involved in less than one of every 30 trades, down from about one of every seven just five years ago, according to exchange statistics. Brokers on the floor, who carry out customers’ orders to buy and sell shares, handled an additional four of those 30 trades. The other 25 were without a middleman.  With demand for their services dwindling, the remaining specialist firms have been shrinking and struggling to survive. One of the more prominent firms, LaBranche & Company, reported a loss of almost $370 million in the second quarter, much of it attributed to a drop in the value of its stake in the New York Stock Exchange.  “Until the specialists and the brokers can make a satisfactory return on their investment on the floor, everything is in question,” said Patrick J. Healy, the chief executive of Issuer Advisory Group, which advises public companies on how and where to list their shares for trading. “Whether the floor can survive is a 50-50 proposition. The answer is, we’ll know soon.”  For their part, exchange officials pointed out that the exchange was just one segment of a growing, global network of trading companies. After becoming a publicly traded company itself last year by merging with Archipelago Holdings, the exchange’s operator merged in April with Euronext, which owned stock and futures exchanges in London, Paris, Brussels, Amsterdam and Lisbon.  Officials of the New York Stock Exchange have considered acquiring the New York Mercantile Exchange, which makes markets in oil, gold and other commodities, according to city officials. But no deal has materialized yet.  Today, what happens on the 104-year-old trading floor on Wall Street accounts for only one-tenth of the revenue of the company, now known as NYSE Euronext.  But exchange officials said that they were revamping their operations to make the floor more integral, not less. The opportunity to have people rather than computers make decisions on a customer’s trade distinguishes the exchange from its all-electronic competitors like the Nasdaq stock market, they said.  “We intend to have the floor as part of our market model as far as we can see out into the future,” said Duncan L. Niederauer, the president of NYSE Euronext. “There are certain things that computers can’t do.”  Mr. Niederauer said he could not predict how much of the trading would ultimately occur there, but he said he did not foresee further shrinkage of the floor. “I don’t see it getting a lot smaller than that,” he said, referring to the two rooms that will be left after November.  One of those rooms is the grand, original trading room that was the centerpiece of the exchange when it was built in 1903. The other is a room indelicately named “the garage,” which was added in 1922. The rooms that are being closed were stitched on in 1969 and 1988. A fifth room was added in 2000 by building an overpass from the floor to a building across Exchange Place, but it was closed in February.  When that last expansion occurred, Richard A. Grasso, who was then chairman of the exchange, had bigger plans. He had persuaded the Giuliani administration to provide about $1 billion in tax breaks and other incentives toward the creation of a new home base for the exchange across Broad Street. But the Bloomberg administration scrapped that plan, which would have been one of the city’s biggest offers to retain a large company.  Two years ago, the city agreed to provide about $650 million in incentives to Goldman Sachs to build its new headquarters near ground zero instead of moving to Midtown. Goldman, which has about 30,000 employees, is thriving now, as the exchange is shedding jobs and shrinking its presence in the city.  Ms. Mogavero, whose husband also was a floor broker until he retired a few years ago, said she hoped that the tighter quarters would revive some of the camaraderie of the more boisterous days when brokers like her weaved from room to room. She applauded the executives who oversee the exchange for not giving up on the floor altogether, as many exchanges around the world have done.  “It would have been easy for them to flip a switch and say: ‘Let’s be electronic. Everybody go home,’ ” she said.  City officials express hope that the executives who run the exchange will find a way to maintain its image as the gold standard of financial markets, but they are resigned to its diminished physical presence and the permanent loss of jobs on the floor.  “The forces that will determine exactly how many people work within the stock exchange or are connected to it are so much larger than the city itself,” said Daniel L. Doctoroff, the deputy mayor for economic development. “The city can’t fight market forces. But I do feel confident that there will be a significant physical presence there. No matter what happens to the N.Y.S.E., that building, with all of the history that it contains, is still going to be viewed as the center of the financial world.”  But in private, city and state officials are fretting about how “to position ourselves to remain the center of global finance if the anchor of the New York Stock Exchange isn’t there for us or doesn’t have the same meaning as it has had for the last century,” said Kathryn S. Wylde, president of the Partnership for New York City.  They understand, Ms. Wylde said, that the key components of exchanges in the 21st century are not people, but computers and technology. “The shift is happening; it’s inevitable, and it’s happening quickly,” she said.  A version of this article appears in print on , on Page 137 of the New York edition with the headline: Next to Downsize On Wall Street? The Exchange Floor. Order Reprints| Today's Paper|Subscribe
As computerized trading reduces the need for face-to-face transactions, the New York Stock Exchange plans to shut two trading rooms.