On a sunny afternoon in west Beijing, on the auspicious eighth floor of a nondescript concrete high-rise, Huai Yang sits with the curtains drawn in his apartment, making his own luck.

For the past six months, 27-year-old Yang has worked mainly from home, mainly from his sofa, tracking and trading bitcoin, and watching the money roll in. The flat itself is modestly sized; Yang moved in in his pre-bitcoin days when he worked variously for a crowdfunder start-up, a branding consultancy and dabbled in hedge-fund management, all of which he describes as “creative financial work”. Now, though, his main focus is bitcoin, which is “much younger, more fun, and much more money”. Yang claims to make up to 1m yuan (£116,000) a month, under the radar of the taxman, purely from trading the online cryptocurrency.

Bitcoin has no physical form but the rewards are very tangible; Yang’s home is packed full of expensive gadgetry, most prominently a mega-sized flat screen smart board, over a metre wide, which Yang uses to chart bitcoin’s rise and fall in HD.

Normally, the graphs on Yang’s screen show bitcoin’s and his own fortunes going up and up. At the time of writing, one bitcoin is worth 6,600 yuan (£768) – recent months have seen the value hover well above 8,000 yuan. The global worth of bitcoin is over $14bn USD (£11.3bn), of which over 90% is in yuan, and Yang and his peers are cashing in. “I want a more splendid life,” he says.

Huai Yang, who trades bitcoin from his sofa Photograph: Naomi Goddard/The Guardian

There’s certainly big money to be made in bitcoin, but it comes at a high risk. Bitcoin was designed to be a peer-to-peer currency, free from interference from government and central banks. Since the currency was launched in 2009, however, the Chinese market, where government interventions are common, has come to dwarf all others.

One such intervention took place in February this year, when the government warned that there would be “serious violations” for trading platforms that failed to abide by strict money-laundering regulations. In line with this, OKCoin and Huobi.com, the two biggest exchanges in China, announced that they would be suspending bitcoin withdrawals for one month.

Incidents like these, which Yang sees as “not convenient, but not [a] problem,” give Chenxing (who asked that I only use his first name) pause for thought. Chenxing, a boyish, skittish 35, has been trading bitcoin for the past four months, after giving up his “too comfortable” job as a geo-information engineer for the government. The government’s pressure on bitcoin platforms is “not so easy to understand,” he tells me. “I’m not sure it’s really about money laundering … they try to control [bitcoin], but they cannot”.

For Chenxing, it’s the system itself that is vulnerable: “Technology changes every day,” he explains. “Maybe tomorrow a hacker can find a way to crack bitcoin … the security is from mathematics. If you can crack the mathematics, bitcoin is nothing.” That’s why, even though Chenxing describes himself as a “believer” in bitcoin, he doesn’t plan to stay involved for the long term.

“It’s really not a stable thing,” he says, both in terms of fluctuating prices and the uncertain technological future of the cryptocurrency. That said, he’s still “making more money” than in his previous government job. In a good month, Chenxing will pocket the cash value of around five bitcoin, which is close to 40,000 yuan, and which Chenxing prefers to have in cold, hard cash.

Chenxing is something of an anomaly in Chinese bitcoin circles, where the general mood is one of evangelical faith in the currency’s potential, especially in an economy where the government often devalues the national currency.

Brendan Gibson, 32, is a United States national who has been in China for six years, trading bitcoin for three. We’ve barely sat down to talk when Gibson takes my phone and downloads the BTC Wallet app onto it, before transferring me the seeds of my cryptocurrency fortune: 0.0027 bitcoin, worth £2.50, which is the amount that everyone in the world would have if the 21m bitcoin in existence were equally divided up between all 7.8 billion of us. He believes that “everybody’s aunt … or grandma” should be using bitcoin.

Brendan Gibson: ‘I’m just kind of fed up with the system.’ Photograph: Naomi Goddard/The Guardian

For Gibson, bitcoin is a way of life. He hopes to be completely bank free in the near future. Hailing from the “shady mortgage industry” of corporate America, Gibson shares Chenxing’s distrustful attitude, but is more concerned about private banks than bitcoin’s technological vulnerability. “I’m just kind of fed up with the system,” he tells me over coffee in a slick café and co-working space from where Gibson does most of his work remotely.

“I don’t think economies should be built on inflated numbers, and I think it’s kind of ridiculous that everybody relies on this inflated number in their bank account when it’s definitely not there … bitcoin and other cryptocurrencies are making it so that we are our own banks, and that’s one less things we have to worry about.” Gibson owns two companies in China, and as far as possible uses bitcoin for all his daily expenses, converting the personal profits he makes into bitcoin to avoid using banks.

One of the commonly cited weaknesses in the bitcoin system is that if you lose your private key to access your bitcoin wallet, the bitcoin within are lost forever. In 2015, it was estimated that up to 30% of all mined bitcoins had been lost, with a value of £625m. Unsurprisingly, plenty of people see this as an opportunity to make some money.

Sun Zeyu, 27, works at a tech start-up based near Beijing’s university district that specialises in bitcoin. His latest project is Coldlar, an offline, physical wallet that stores users’ bitcoin and can be accessed by scanning a QR code. Bitcoin security is a “tough question”, Sun tells me, which is why he and his colleagues designed a product that allows people to circumvent bitcoin platforms and have even greater control over their bitcoin. “Now that the value [of bitcoin] is going up,” he explains, “people really realise the importance of security.

Before, when we just traded one or two coins, people didn’t mind, [but] now the value of bitcoin is much bigger”. Sun got involved with bitcoin while at university after attending a seminar run by Huobi, one of the biggest trading platforms in China. Like his flashier friend Yang, Sun wanted money, and lots of it. He won’t tell me exactly how much he earns, but assures me that it’s “hundreds or thousands” times more than the 10,000 yuan per month he was earning when he first dabbled in bitcoin three years ago.

His money comes from both his trading activity and his company salary. With the growth of bitcoin and related products like his Coldlar wallet, Sun believes that in 10 years’ time, the value of the cryptocurrency will be “one bitcoin, one house in Beijing”. Minor shocks to the system, like the recent suspension of bitcoin withdrawals in China, are “just like breathing,” he insists, and the inhalations of profit dwarf any other bumps in the road.

Sun Zeyu at work. Photograph: Naomi Goddard/The Guardian

Despite the solitary nature of their work, Yang, Sun, Gibson and Chenxing are all sociable creatures. Gibson is connected to hundreds of bitcoin aficionados in China, and has introduced close to 1,000 new people to the technology (although how many are like me, with £2.50 lying dormant in an unused wallet, is unknown), such is his enthusiasm for the cryptocurrency. Chenxing cites the social side of the bitcoin scene in Beijing as one of the main attractions of staying in the industry and the city.

“I can meet some fun people who really love bitcoin … I think most of the people who like bitcoin are people who like freedom” he says. Yang, however, takes a slightly harder-edged approach. He has little patience for sceptics: “Yes, bitcoin is a risk. Why should I have to discuss these things with [people concerned about the security]? I earn my money, that’s enough. I don’t waste my time explaining bitcoin … [if] you’re not my client”. In some ways, Yang concedes, the less people understand bitcoin, the better it is for him. At the moment, the industry is “like an ATM” for him and his peers, and he’s perfectly happy for things to stay that way.

In the fast-changing world of the crypto-currency, nothing seems to stay the same for long. Whether it’s unpredictable government interventions, or debates within the community about how the industry can and should be scaled, general growth in value thus fair doesn’t necessarily suggest anything about the future of bitcoin, despite the faith of its adherents. Gibson makes the point that bitcoin has only been around for nine years; it took PayPal at least 10 to properly catch on.

In Japan it has recently been recognised as legal tender. It’s unlikely that the same could ever happen in China, no matter how much its popularity continues to balloon. Chenxing, who has years of insider experience, is sure that “[the government] will never accept a thing that’s not built by themselves”. Many bitcoin traders in China are in it for the long haul, confident that they can ride out any governmental interferences, as long as they have access to the internet. Chenxing, however, is more paranoid. His final thoughts on bitcoin are: “I never feel secure”.