The last time Marc Kenigsberg travelled to London, he messaged his cryptocurrency friends on WhatsApp to ask who would be around. One of the guys in the chat offered to pick him up at the airport.

On the hour-long ride to Cambridge, they talked about how virtual money would cause the same upheaval in the financial system that email did to the post office.

“I came to Bitcoin because of the tech, but when I really fell in love with Bitcoin was when I met the people who also love Bitcoin,” said Kenigsberg, a 38-year-old South African. “I’ve never met a community that’s as welcoming or as giving or as honest.”

The outside world sees them as bros, and some do indeed fit the stereotype of anarchists trying to crush the world’s central banks by day while partying in strip clubs by night. But many reject that scene and are, above all else, wonks — driven by passion for the potential to turn coding, public ledgers and complex mathematics into a revolutionary technology. They hope to dramatically change the world for the better and unleash money from the control of a ruling elite. Some don’t even care about getting rich in the process. They’d rather “hodl,” crypto slang for holding their investments.

It’s a group that’s also overwhelmingly male. And that brotherhood cuts both ways. Many help each other with advice, airport pickups and even financial strife. But many women find themselves locked out. For them, the culture can be inaccessible or even openly hostile. A Bitcoin conference in Miami that slated few women to speak, and then adjourned to a strip club for a networking session, was just the latest flareup in that struggle. Some women who complained were harassed again online.

More than 90 per cent of the Bitcoin community is male, and almost half are between the ages of 25 and 34, according to researcher Coin Dance. Many of them came to the crypto world from male-dominated fields such as coding and finance, or from conversation sites like Reddit, where 69 per cent of American users are male.

Ironically, in a system designed to eliminate reliance on trust — of governments, of banks, of third parties in a financial transaction — the men who support that system have woven a web of belief in each other that flourishes both on and offline.

When Luke Dashjr’s Tampa home was hit by a hurricane in September, the Bitcoin community rallied on Medium, Reddit and Twitter to raise five Bitcoin, or about US$20,000 at the time, to help him repair damages. The gift was extended by another 3.5 Bitcoin to get internet service up and running so Dashjr could continue coding.

And when Bitcoin evangelist Andreas Antonopoulos went public with his financial problems, hundreds of like-minded bros who knew him only online came to his aid. Antonopoulos, who has written several books on Bitcoin and is a popular speaker on the subject, is now a Bitcoin millionaire.

The growing global community of mostly millennial men emerged a little over a decade ago from a mailing list of techies discussing cryptography and how to build a digital currency. In October 2008, Satoshi Nakamoto’s nine-page PDF containing the blueprint for Bitcoin was sent to the group, whose members called themselves “cypherpunks.”

As Bitcoin became more popular, its passionate followers multiplied in number. People drawn to its anti-establishment roots and business potential congregated in online forums such as 4chan and Reddit, where they debated, tipped one another to the latest news and exchanged memes, which have since become a unifying language.

For women, however, crypto Twitter can be a minefield. Jennifer Leigh, a former full-time poker player who now trades cryptocurrencies and makes infographics that explain the tech behind them, said her Twitter posts are often met with disparaging remarks based on her gender.

The 2,300-member Facebook group that she moderates to support and encourage women in cryptocurrency is peppered with complaints. One member posted last month, “Why is the main group full of such complete JERKS? Just … wow.”

Still, Leigh said she sees more good than bad and is proud to be a part of what she called a digital revolution.

“I’ve learned to shrug off the misogyny and trolling of women,” said Leigh, 33. “I always tell the ladies that it’s not you. And they should say this isn’t OK and not let things like that bother them because it’s just coming from someone on the internet who’s super insecure.”

Brothers do sometimes fight among themselves. Disagreements over how to scale Bitcoin have resulted in bitter public clashes. Last year, the spat came to a head as a group was pushing to upgrade the Bitcoin network with technology that threatened to disrupt the main chain. Insults were tossed, long rambling posts were written on both sides, and there was even an alleged  death threat.

Despite the controversies, Kenigsberg said he believes his involvement in digital money is about supporting a system that will change the world and being part of a community that’s not only smart but, at least to him, kind.

“I’m very idealistic about the tech,” Kenigsberg said. But “the nature of Bitcoin’s community is one of its greatest strengths and one of the best benefits to being a Bitcoin holder.”