NEW YORK — “What’s up, Lenny,” a broker on the floor of the New York Stock Exchange says, just before the ringing of the Pavlovian bell that opens the financial market. Lenny answers this morning bid with the customary response: “What’s up.”

Posed less as a sincere inquiry into one’s well-being than as a passing nod to another day in the financial scrum, the greeting can also be interpreted in these uncertain times as a question baldly seeking reassurance: What’s up?

Stocks? Hopes? Layoffs? Blood pressure?

Leaving unexplored the phrase’s deeper meaning, the two brokers melt into a blue-coated sea on the main floor of the exchange, where the Lennys have come to personify the amorphous, temperamental, life-altering thing called Wall Street — an all-encompassing name for the stock market, the economy, your 401(k).

From the balcony above this gladiator’s pit, photographers crouch to capture expressions of joy, of anguish, of bewilderment, that are then presented as clues to how we should feel — even though that broker’s frown may reflect nothing more than digestive disagreement with a wolfed-down fried egg sandwich.

Not long ago, a floor broker named Danny Trimble cocked a finger to his head and placed it against his temple, for reasons unrelated to the market; soon an image of Trimble “shooting” himself made the newspapers. No matter that he is not a hedge fund manager, bank CEO or fat cat; no matter that he is just a financial foot soldier from Jersey, hoarse from shouting at his son’s Pop Warner football games.

Trimble, 41, works at the edge of the exchange’s main floor, shoulder to shoulder with six other men in a booth the size of an elevator car. Not everyone graduated from college, but all are resident scholars of the hurly-burly floor, educated in reading markets, hunting for matches and executing buy-and-sell orders. They are worth their commissions, they say, because they provide things a computer cannot, things like experience, intuition — a “feel.”

A quieter place

Crammed into this booth with no place to sit are Mike Ackerman, Paul Davis, Billy Johnson and Nick Stratakis, of B and B Securities; Trimble and Chris Martin, of Greywolf Equity Partners; and Ralph Roiland, a clerk. Scrappy independents, all; no one works for Goldman Sachs.

Still, when they step onto Broad and Exchange streets to breathe the autumn air, they sometimes get blamed for the world’s economic crisis. “You walk out there and people think you’re what’s wrong with this country,” says Martin, father of three, of Morristown, N.J.

With the opening of the market imminent, the men in the booth send instant messages to clients, asking, hoping, for interest in trading stock. But the volatile activity in recent weeks has unnerved many investors; some respond with noncommittal “Thanks” and “I’m away from my desk.”

At 9:30 on the dime, the opening bell rings, clanging off the century-old walls of white marble, the ceiling of gilded gold. Brokers rush to the center of the floor, where specialists in individual stocks track the last best data. Shouts of “Buy off 10,000, pair off 10,000,” and “How’s Marathon?” feed the low roar of business.

After awhile, though, quiet returns. Brokers gaze at computer screens in their booths, some to monitor stocks, some to play virtual games. In one corner, a man is deciphering a crossword puzzle, while three beside him play cards. The stock exchange has a different rhythm now, its denizens say, because of technological advances and the shrinking of the once-dominant house firms. It’s not like before.

Many of the men, and it’s still almost all men, remember the days when they stood several deep around the specialists, nudging, pushing, staying put for several straight hours, shouting “Squad!” for pages to hustle handwritten notes to clerks on the wings, jockeying at the banks of phones now hanging from hooks like relics.

Those were the days when black humor and practical jokes helped to blow off steam and show affection for comrades.

The one-liners would fly minutes after, say, the space shuttle Challenger went down. A trader would return to work, disfigured, after a serious car accident to find at his station a toy car, burned and crushed. And he would laugh.

Billy Johnson, 48, a burly former firefighter from Oceanport, N.J., recalls how his floor colleagues helped him to toast his approaching marriage: by ripping his jacket and covering him with shaving cream, perfume and potato chips.

Fading scene

The jokes and put-downs still go on, and lately someone has been beeping a horn concealed in his jacket. But the humor is not quite as black.

“A lot of that stopped after 9/11,” says Doreen Mogavero, 53, an experienced floor broker who points out that ground zero is a couple of blocks away. “It wasn’t that funny anymore.”

Gone, too, is that loud physicality of the floor. Headsets and hand-held computerized pads mean less running around, fewer clerks, softer voices, a smaller chance for error. Those technological advances have opened the market to just about anyone with a computer, making floor trading seem almost quaint. Many traders retired rather than change their ways; others got laid off, including one now walking through the exchange. Selling insurance, someone says.

Of the 1,366 broker’s licenses available for an annual fee of $40,000, only 553 are being used. In 2006, there were 3,534 people working on the floor; today, there are 1,273.

“The stress now is the lack of business,” says Benedict Willis III, 48, a senior broker who started here in 1982. Moments later he is interrupted by applause. It is the sound of a lost job: A floor broker of 20 years has just been laid off from a major firm, and now his colleagues are showing their respect.

“They’re clapping him off,” Willis says. “It’s the second one this week.”

One of the brokers in that small booth, Mike Ackerman, leads a Scandinavian delegation on a brief tour of the exchange, past computer screens flashing red and green, past taped-up photographs of family members, closed baseball stadiums and the Lower Manhattan skyline when it was intact. As he takes them to the balcony, a delegate asks a question in halting English: Does Ackerman feel personally responsible for the collapsing economy?

Good question, answers Ackerman, 39, father of three, from Basking Ridge, N.J. Good question. But — no.

He and all the people down on that floor are executing trades on behalf of others, using a hybrid method that combines a computer’s technology with a human’s gut instinct. They do not deal in subprime mortgages; they do not get golden parachutes. But hey: Good question.

These brokers make money whether the market goes up or down; their earnings depend on the volume of trades, and the floor averages 117 million orders a day. Still, they prefer north to south. “It’s political economics,” Willis explains. “We want to reassure investors that it’s OK to come back.”

Tomorrow the market will plummet in the very last minutes. Beaten brokers will repair to bars like Bobby Van’s across the street, where the bartenders know their drinks before they’ve ordered.

But right now the market climbs with every tick toward the 4 p.m. closing, as though willed to rise by all the Lennys now eyeing the electronic board. Up, up, up.

“Two minutes to go,” someone says at 3:58. “A lifetime.”