He’s the Billy the Kid of bitcoin.

Twenty-one-year-old Manhattan con man Nicholas Truglia hacked into the phones of Silicon Valley bigwigs to try to steal their cryptocurrency — and in one instance, pulled it off, authorities said Tuesday.

Truglia, who claims on Facebook to be a Harvard University student, targeted the Who’s Who of the Bay Area from his cushy West 42nd Street high-rise apartment, officials said.

“It’s a new way of doing an old crime,” said deputy DA Erin West of Santa Clara Superior Court to The Post. “It’s a pervasive problem, and it involves millions of dollars.”

Truglia stole $1 million from San Francisco father of two Robert Ross in the SIM-swapping scheme, according to officials and court records.

Ross watched helplessly on Oct. 26 as his phone went dark and $500,000 in a Coinbase account and another $500,000 in a Gemini account vanished in seconds. It was his daughters’ college fund — his entire life savings, West said.

Truglia allegedly converted the cash to cryptocurrency and moved it into his personal account, authorities said.

His other marks include Saswata Basu, CEO of the block-chain storage service 0Chain; hedge-funder Myles Danielsen, vice president of Hall Capital Partners, and Gabrielle Katsnelson, the co-founder of the startup SMBX.

Although Truglia didn’t score any bitcoin with his other victims, he was able to take over their phones, court records show.

SIM-swappers persuade cellular customer-service representatives to port victims’ phone numbers to their phone, giving them access to the device’s account information.

“You’re sitting in your home, your phone is in front of you, and you suddenly become aware there is no service because the bad guy has taken control of your phone number,” West said.

West is part of the Santa Clara REACT task force, which pursues SIM-swapping cases nationwide.

The team, which includes federal agents, flew to New York on Nov. 14 and arrested Truglia at his apartment, authorities said.

West said agents found a “hardware wallet, a device almost like a thumb drive” in the pad, and they were able to recover $300,000 in stolen funds.

Truglia is being held at the Manhattan Detention Complex pending extradition to Santa Clara, Calif., where he faces 21 felony counts related to a total of six victims, officials said.

The allegations stem from a one-week hacking spree that started Oct. 8 and include charges of grand theft, altering or damaging computer data with the intent to defraud and using personal information without authorization.

Prosecutors believe Truglia was working with a crew.

“The takeaway here to the hackers is, ‘We don’t care where you’re located, we are a task force based in Silicon Valley, and our reach is nationwide,’ ” said West.

Truglia was last in the news in September when he called the cops on four friends, who he claimed tried to steal a thumb drive with account data linked to $1.2 million in bitcoin.

“It’s pretty common for people to target people who have a lot of cryptocurrency,” Truglia said at the time.