Walking into the crowded hotel conference room, Andrew Batey looked like any other tech guy attending ETHDenver, an annual cryptocurrency conference. A venture capital investor based in Florida, Mr. Batey wore a black sweatshirt emblazoned with the logos of more than a dozen crypto companies, with names like LunarCrush and bitSmiley. He had arrived in town with some expensive footwear — a pair of Off-White Air Jordans, the type of sneaker, he said, that people usually don’t take out of the box.

Mr. Batey, however, was at the conference not to network with fellow crypto enthusiasts but to fight one of them — live on YouTube. At the hotel, a short drive from the conference convention center, he was preparing for his official weigh-in, the final step before a fight the next evening in an arena packed with crypto colleagues. Under the watchful eye of a representative from the Colorado Combative Sports Commission, Mr. Batey, 40, stripped down to his boxers, which were adorned with a cartoon Santa Claus riding a golf cart.

He weighed in at just under 195 pounds, on target for the fight. The bare-chested venture capitalist raised his biceps and flexed for the cameras.

The nation’s tech elite, not content with unfathomable wealth and rising political influence in Washington, have recently developed a new obsession — fighting. Across the United States, men like Mr. Batey are learning to punch, kick, knee, elbow and, in some cases, hammer an opponent over the head with their fists. The figurehead of the movement is Mark Zuckerberg, the billionaire chief executive of Meta, who has charted his impressive physical transformation from skinny computer nerd to martial arts fighter on Instagram, one of the apps he owns. A recent post showed Mr. Zuckerberg, dressed in gym shorts and an American flag T-shirt, grappling his opponent to the ground.

The tech industry’s newfound devotion to martial arts is one facet of a broader cultural shift that has upended U.S. politics. Many of these tech founders turned fighters are chasing a testosterone-heavy ideal of masculinity that is ascendant on social media and embraced by President Trump. An enthusiastic practitioner of Brazilian jujitsu, Mr. Zuckerberg, 40, lamented this year that corporate culture was getting “neutered” and was devoid of “masculine energy.” In 2023, Mr. Zuckerberg’s fellow billionaire Elon Musk, a longtime corporate rival, challenged him to a televised cage match. The fight never took place, though Mr. Musk suggested at one point that he was willing to do battle in the Roman Colosseum.

Ancient Rome is, in some ways, a useful reference point for this era of ultrarich braggadocio. The wealthiest Romans were fascinated with violent combat. The emperor Commodus even joined in the gladiatorial contests, claiming he had fought as many as 1,000 times. By the early 20th century, fighting was still a popular pastime for the elites: An avid boxer in his Harvard years, Teddy Roosevelt regularly sparred at the White House.

These days, the rise of mixed martial arts is part of a cultural revanchism that has thrived in the so-called manosphere, where hypermasculine online commentators complain that women have become too powerful in the workplace. In this corner of the internet, men are seeking to reclaim a kind of aggressive masculinity that came under scrutiny during the #MeToo era.

It’s the latest iteration of a phenomenon that the feminist writer Susan Faludi described in her 1991 book, “Backlash,” about how men have historically reacted to advances in women’s rights. In an interview last month, Ms. Faludi said the growing male obsession with fighting amounted to “a boy’s idea of what it means to be a man.”

“Living out this childhood fantasy of being pro athletes, that’s just puerile,” she said. “These guys need to discover yoga.”

The urge to fight has recently spilled over from the tech billionaire class to the industry’s trenches, where mere decamillionaires and millionaires now practice martial arts in increasing numbers. Mr. Zuckerberg’s transformation offered a “beacon of hope” for other executives, Mr. Batey said. “Dreamers can latch on to something like this and say, ‘Maybe it’s possible.’”

Until lately, though, a run-of-the-mill tech founder hoping to flex his muscles on TV would have had limited options. Then a company called Karate Combat glimpsed a market opportunity.

A ‘Clout-Forming Exercise’

Most of the tech world’s aspiring fighters have a crucial thing in common: Before they started pursuing their extravagant new hobby, they made a lot of money.

In 2018, Mr. Batey founded Beatdapp, a company that develops software to eliminate fraud in music streaming. He also runs a venture capital firm, Side Door Ventures, that invests in crypto start-ups. Like many of his colleagues, Mr. Batey is the consummate pitchman. Even the miracle of life is an opportunity for crypto evangelism. When friends are expecting a baby, Mr. Batey said, he gives them Bitcoin (worth more than $100,000 at today’s prices) and asks them not to sell until their child turns 18.

“I always hated giving people like a onesie,” he said. “I hate the concept of giving somebody something that they could easily afford.”

Two years ago, Mr. Batey’s venture fund invested $500,000 in Karate Combat, a would-be competitor to the Ultimate Fighting Championship. The league operates as a hybrid between an athletic competition and a tech start-up. Rather than offering traditional shares, Karate Combat gave Mr. Batey’s firm Karate tokens — a cryptocurrency that fans can wager on Karate Combat fights, which stream on YouTube as well as TV channels like ESPN Deportes.

Karate Combat’s primary business is professional fighting — mixed martial arts contests featuring seasoned athletes, some of whom also fight in U.F.C. (A representative for Karate Combat declined to reveal how much money the league generates.) Last year, the company created a new competition for amateurs and started offering it as the undercard at pro events, which are sometimes held at crypto conferences. The competition was called Influencer Fight Club, and its premise was simple: Put a couple of tech guys in the ring and see what happens.

Karate Combat’s fights have an extensive following on Crypto Twitter, and Influencer Fight Club has helped attract more of those super-online fans. Over the last 18 months, the competition has featured some big names in the crypto world, including Nic Carter, a venture investor known for his combative posts on X, where he has attacked government regulators and questioned the efficacy of Covid vaccines. At a crypto conference in Nashville last summer, Mr. Carter, boasting an impressive physique, knocked out a tattooed crypto marketer in one round. On social media, he was hailed as “kingly” and adopted the nickname “Tungsten Daddy.”

“This is an amazing clout-forming exercise,” Mr. Carter said in a recent interview. “Not to be cynical about it.”

Mr. Batey attended an Influencer Fight Club event in Austin, Texas, last year and decided he wanted to fight, too. Once an amateur athlete who dabbled in boxing, he had gained a lot of weight as his career took off, eventually carrying 283 pounds on his 5-foot, 10-inch frame. He was about to turn 40 and needed to get into shape for health reasons. But he also wanted to have the sort of athletic experience usually reserved for serious fighters, who sometimes train their entire lives for the chance to compete on TV.

“This is my 40th birthday party — me fighting,” Mr. Batey explained. “Maybe it’s a midlife crisis.”

For four months, Mr. Batey put his career on hold and spent $75,000 on a trainer, a nutritionist and a rotating cast of professional sparring partners. After the fight was scheduled for ETHDenver, a conference devoted to the cryptocurrency Ethereum, he booked a block of nearly 30 hotel rooms to accommodate his friends and supporters.

The training was transformative, Mr. Batey said. He developed muscles he hadn’t seen in 20 years. Masculinity “doesn’t factor into how I think about it,” he said. “But I definitely feel more masculine.”

At first Mr. Batey had trouble finding a suitable opponent. Last year, he went to New York to spar with Billy McFarland, the creator of Fyre Festival, the fraudulent music event that inspired a Netflix documentary. But Mr. McFarland backed out after Karate Combat refused to guarantee him a $100,000 appearance fee, Mr. Batey said. Mr. McFarland declined to comment. (Payouts vary across Karate Combat’s influencer fights. One contract reviewed by The New York Times offered a $2,000 participation fee and a bonus of $10,000 in Karate tokens if the fighter landed a knockout punch.) A second possible opponent declined to fight Mr. Batey over concerns about the venue: He couldn’t appear at an Ethereum conference because he was loyal to Solana, a rival cryptocurrency.

By January, Mr. Batey was worried the fight wouldn’t come together in time. Then a solution emerged: Chauncey St. John, a crypto entrepreneur based in upstate New York.

Mr. St. John does not seem much like a fighter. “I’ve got this Mr. Rogers vibe to me,” he said recently. But he had endured his share of hardship in the crypto world. In 2021, he founded Angel Protocol, a start-up that aimed to help charities raise money using crypto. Unfortunately, he steered his clients toward an investment platform tied to Luna, a digital currency whose price crashed overnight in 2022, setting off a meltdown in the crypto markets that erased much of what the charities had raised.

After the Luna crash, Mr. St. John, 38, retreated from public view. He reimbursed the charities with money his firm had saved up and embraced Christianity, searching for meaning in the worst moment of his career. One day in January, Mr. St. John was scrolling on his phone when he glanced at a group chat that included other crypto enthusiasts. His eyes fell on a message from an industry colleague who goes by the nickname “The Degen Boii”: Karate Combat needed a fighter for ETHDenver.

The invitation “felt like testimony from God,” Mr. St. John said.

For part of his life, he said, he didn’t fit in with other men, and sometimes wondered if he was gay. (He is now married to a woman.) Here was a chance to re-enter the crypto industry, re-establish his public profile and lay claim to what he calls “divine masculinity.”

“We’re trying to make it so equality means there’s no difference between the genders,” Mr. St. John said. “There’s a healthy masculinity that’s been thrown out, baby with the bathwater-style.”

He signed a contract and booked a flight to Denver.

Nerds Trying ‘to Man Up’

A few hours after the weigh-in, Mr. Batey drove to the Stockyards Event Center, a sprawling venue on the outskirts of Denver where Karate Combat had erected four sets of stands, overlooking a pit lined with mats. An extensive entourage came along: two trainers, a couple of fighters from Mr. Batey’s gym and a filmmaker shooting footage for a documentary about his transformation.

With 24 hours to go until the fight, it was time for the ceremonial face-off, an opportunity for ostentatious trash talk. On the edge of the pit, the league’s president, Asim Zaidi, summoned the two crypto founders forward.

Mr. Batey drew close to Mr. St. John, almost nose to nose. “Are you gonna kiss me?” Mr. St. John asked.

“We’ll find out,” Mr. Batey replied.

When the theatrics concluded, Mr. St. John walked down to the pit. Unlike Mr. Batey, he had not had much time to prepare; his entourage consisted of a single person, a trainer with no pro fighting experience, whom he had met a few months earlier in the “Indigenous spirituality community,” he said. Alone in the ring, Mr. St. John started to shadow box.

A few feet away, Chiheb Soumer, a former professional kick boxer, was watching him closely. A native of Hamburg, Germany, Mr. Soumer, 36, had once worked as an in-house trainer for Snap in Los Angeles, teaching tech employees how to box. He traveled to Denver as Mr. Batey’s trainer.

“I love to see these nerds all of a sudden try to man up,” he said.

Even by martial-arts standards, Mr. Soumer cuts an uncompromising figure, dispensing blunt insults in a deep, accented voice, vaguely reminiscent of Arnold Schwarzenegger. He is particularly attuned to any sign that someone is “soft” — an unforgivable frailty that, in his view, explains all manner of embarrassing conduct.

“That’s a very soft statement,” Mr. Soumer had observed just a few hours before the face-off, when Mr. Batey lamented that he’d had to give up lattes to lose weight for the fight.

Mr. Soumer was unimpressed with Mr. Batey’s opponent — or “this kid Chauncey,” as he called him. “No arms, no shoulder,” he said, with the clinical air of a horse breeder offering his verdict on a wobbly foal. Outside the Stockyards, Mr. Soumer mimed a series of stuttering lunges, while the rest of Mr. Batey’s entourage roared with laughter.

“Bro, soft,” Mr. Soumer said. “Soft like butter, bro.”

Mr. Batey grinned. “I’ve never had more confidence for anything in my life,” he said.

He turned to Mr. Soumer. “After I knock him out, should I donate my winnings to his charity?”

“No,” Mr. Soumer replied. “Keep it for yourself.”

In the Ring on Fight Night

On fight night at the Stockyards, the enemy combatants warmed up a few feet from each other as the arena slowly filled with spectators — men in crypto T-shirts and backward baseball caps, swigging beer and taking photos. At 6 p.m., a roar spread through the building, as Mr. St. John and Mr. Batey slid into the pit.

What followed more closely resembled a schoolyard scrap than a professional martial-arts bout. The choreographed moves that Mr. Batey had rehearsed were nowhere to be seen. Over and over, he threw punches and missed, lunging forward and then lurching back. Mr. St. John swung his arms wildly, whirling in a circle, like a helicopter. Next to the pit, a panel of announcers offered live analysis for the YouTube audience.

“What they lack in technical, they make up for in the heart,” one commentator said. His partner offered a blunter assessment: “It’s hilarious.”

By the end of the first round, Mr. Batey’s nose was bleeding heavily. But soon he forced Mr. St. John to the ground and straddled him, raining punches down onto his head. Within 10 seconds, the referee intervened: Mr. St. John couldn’t continue. It was over.

Mr. Batey held his arms aloft and started to dance, thrusting his pelvis toward the crowd. “I just want to thank my wife,” he told the cheering crowd. “Thank you for supporting me, making my meals, putting the kids to bed.”

Backstage, Mr. St. John was smiling. “I didn’t embarrass myself,” he said. All the effort had been worth it. He would happily do it over again

That night, Mr. Batey went out to celebrate. He had showered, changed and cleaned up his face, except for a single streak of dried blood that was intact on the bridge of his nose. At the entrance to a party near Civic Center Park, Mr. Batey informed the bouncer that he had featured in “a pro fight tonight, a fight on TV.”

The bouncer didn’t seem impressed. But Mr. Batey found a more appreciative audience on the dance floor, where his friends swarmed him, offering hugs and fist bumps. Soon a chant went up: “Batey, Batey, Batey, Batey.”

Away from the group, Mr. Batey confided that at the arena, not long after the fight, he had approached Mr. St. John to express his respect and gratitude — and to make clear that he was “proud of him, as a human.”

Mr. St. John had fought hard, Mr. Batey said. Maybe someday they would be friends.

“He’s a good guy,” Mr. Batey said. “We’re both just good dudes.”

Kitty Bennett contributed research.