“Hey Tucky!” shouts a trader as Peter Tuchman zips towards the floor of the New York stock exchange. “Where are we?” barks Tuchman. “Down,” comes the reply. Tuchman gives an expressive shrug and marches on.

Everyone at the NYSE knows Peter Tuchman, and so do you. You may not know his name but he’s that guy – the one who looks like Albert Einstein, whose mug pops up every time the world’s media covers the financial markets. Throwing his hands up in horror or covering his mouth in shock when the markets crash, clicking his hands above his head flamenco-style or jumping for joy like a real-life Muppet as markets hit new highs.

Like most celebrities in real life, Tuchman is smaller than he looks. Twin clouds of white hair, echoed by snowy facial fuzz, frame a bald pate that slopes gently down to expressive eyes on a face that seems perpetually in motion, as are his hands and feet. Tuchman is a human emoji, a one-man metaphor for the mood of the market. But don’t be fooled by the clowning – Tuchman is a cool cat. What you are seeing is not necessarily what he is thinking.

Tuchman, 60, came late to fame. The born-and-bred New Yorker had already been working on the floor of the NYSE for some 20 years when he first made the front pages. It was 2007 and the financial crisis was dominating the news cycle. On another day of wild swings Tuchman, snapped mouth agog, appeared on the front of the New York Post. “I had just received the bill for my son’s barmitzvah and it was way more money than I anticipated,” jokes Tuchman.

Peter Tuchman on the stairs of the New York stock exchange beside the signatures of all the past bell ringers. Photograph: Joshua Bright for the Guardian

The photo went viral and sparked a trend that has continued to this day. “The cameras sort of went towards me and it just sort of took off on its own,” he says. “Photographers noticed that if they took a picture of me, it would end up in the paper.”

He’s appeared on thousands of front pages, in news reports in the UK, China, Japan. Tuchman gets recognized when he travels on the subway. “It’s crazy,” he says.

After the recession stock markets hit the doldrums and Tuchman’s picture count dropped. Now he’s back. Under Donald Trump stock markets have hit new highs and volatility is back with tweets, trade rows and reconciliations and Trump’s attacks on the Federal Reserve sending markets into a tizzy.

On the day we meet the Dow lost close to 800 points as Trump declared he was “a Tariff Man” – signalling another downturn in China’s tense trade relations with the US and up popped pictures of Tuchman on CNN and other outlets. In the short term Tuchman expects more wild days but he’s bullish about the future. “The fundamentals haven’t changed,” he says.

Tuchman, has earned the right to wear sneakers on the floor of the New York stock exchange. Photograph: Joshua Bright for the Guardian

Tuchman moves fast, snatching bits of conversation with his co-workers as he whizzes around the floor. Flouting the NYSE dress code, Tuchman slips into a pair of New Balance sneakers before hitting the trading floor. The night before he had warned me and the photographer to adhere to the NYSE’s formal dress code, so why is he different? “’Cos I’m special. After 30 years you get to wear sneakers,” he laughs.

Rules bend for Tuchman. He loves the New York stock exchange and they love him; he’s basically the exchange’s mascot these days. There are Tuchman dolls, he has his own range of stickers and hats, he has organized an exhibition of street art – one of his passions – on one of the exchange’s most storied floors.

“How do you become happy? Do what you love to do,” he says.

Tuchman started on the NYSE in 1985 as a teletypist and worked his way up to being an independent broker. His father, a doctor, had a patient who ran a firm on the floor. “I loved business and I loved the environment … the frantic screaming and yelling. That’s my nature right. I thrive on chaos.”

But while he may look like he’s taking each day’s losses and wins personally, he doesn’t take the job home with him – or at least he tries not to.

His sangfroid, Tuchman says, comes from his parents. Marcel and Shoshana Tuchman were Holocaust survivors who were imprisoned in Auschwitz and Bergen-Belsen. “My father was a slave laborer for Siemens Corporation, which is still a public company here,” he says, nodding ruefully at the trading floor.

Tuchman in front of Benny Jr, 2014 by Mister E, one of the works in the street art show he curated inside the New York stock exchange. Photograph: Joshua Bright for The Guardian

His grandmother was murdered in front of his father, most of whose family were also murdered by the Nazis. “As was my mother’s,” he says. “My father went up against Josef Mengele, the death doctor [who performed deadly experiments on Auschwitz prisoners], as did my mother. My mother’s whole family was gassed. They could have come out of that, you know, being angry and depressed, negative-minded people; they didn’t. There are two options in this thing. You can come out of challenges trying to devour every day and looking at life as if the cup is half-full or you come from a negative point of view that you’re a victim and the cup is half-empty. I vote for the former.”

Marcel Tuchman, who worked until he was 93 teaching medicine, died earlier this month aged 97. His son was back at work the next day. “My father always said: ‘When I die, cry and go to work.’ That was his advice.”

Tuchman says one of his father’s biggest regrets was the loss of the “humanist factor” in medicine. The swapping of the human touch for machines and data as opposed to “holding the patient’s hand and saying: ‘How are you feeling?’ It’s the same thing here for me, it’s, you know, that human thing.”

Tuchman refuses to dispense with his notepad. Photograph: Joshua Bright for The Guardian

That’s the irony of Tuchman’s celebrity. It comes as the human factor is disappearing from trading. Stock markets such as Nasdaq don’t have traders like Tuchman. Even most of NYSE’s stock trading is done from a far less photogenic data centre in New Jersey. Critics have dismissed the traders who remain as marketing and “a bunch of clapping seals”, which would make Tuchman the prince of the colony. Is he just the human face the NYSE wants to present in an increasingly robotic world?

Tuchman could not disagree more. When panic hits the market, humans add a “restraint of time and an impulse”, he says, that algorithms cannot replicate. Like a plane on automatic pilot, Tuchman argues, everyone is happy to leave the computers in charges until the flight hits turbulence. Then you want the pilot in charge.

“We’re in a world of hacking, technological blips and problems. There are crazy headlines and news, there are tweets,” he says, rolling his eyes. “I’m a firm believer that humans are a better gauge [of when markets need to hit the pause button] than computers,” he says.

“I don’t think algorithms will fully replace humans at NYSE,” he says. “The more we rely on technology, the more important it becomes to have humans involved.”