In the United States, Charles Herman, a 29-year-old small business owner in Charleston, S.C., became obsessed with virtual currencies last September. He said he now felt like he had wasted 10 months of his life trying to play the markets.
While he is essentially back to the $4,000 he put in, he has soured on the revolutionary promises that virtual currency fanatics made for the technology last year and has resumed investing his money in real estate.
"I guess I thought we were 'sticking it to the man' when I got on board," Mr. Herman said. "But I think 'the man' had already caught on, and had an exit strategy."
Much of the anger that investors feel is toward the smaller virtual currencies, or alt coins, that entrepreneurs sold in so-called initial coin offerings. These coins were supposed to serve as payment mechanisms for new software the entrepreneurs were building.
But almost none of these companies have delivered the software they promised, leaving the tokens useless, except as speculative assets. Several coins have been exposed as outright scams.
"I think I'd like to see most alts go to zero before I feel like the whole space isn't overpriced," Mr. Herman said.
Bitcoin has generally held on better with investors. It is down about 70 percent from all-time highs, rather than the 90-percent losses that lesser-known digital tokens have suffered. But it, too, has struggled to win much usage beyond speculative investments.
"We also saw that Bitcoin isn't ready for mass adoption and day-to-day use," Mr. Herman said.
Despite this pessimism, the social networks where cryptocurrency fanatics gather to trade information are full of people talking about their intention to hold on to their coins, in the hope that they will recover once the technology has time to catch up with the hype.
Tony Yoo, 26, a financial analyst in Los Angeles, invested more than $100,000 of his savings last fall. At their lowest point, his holdings dropped almost 70 percent in value.
But Mr. Yoo is still a big believer in the idea that these tokens can provide a new way to transact online, without the big corporate middlemen we rely on today. Many of the groups that raised money last year are still working on the products they promised, with lots of serious engineers drawn to the projects.
"There's just so much more behind this new wave of technology and innovation that I'm sure will take over our society in due time," Mr. Yoo said.
With prices down so much, he said he was actually looking to put more money into the markets.
That thinking has been encouraged by the people who invested in Bitcoin in 2013, when it first topped $1,000. That bull market was followed by a crash in which the price of Bitcoin dropped more than 80 percent. But after a long fallow period, the price recovered. Even with recent losses, the value of one Bitcoin is hovering around $6,500 — up more than 500 percent from the peak of 2013.
"Five years ago, I was broke, unemployed, and ashamed to use my real name," Ryan Selkis, a popular virtual currency personality, wrote on Twitter last week. "For the new fanatics, stick around for your own 14 month, 85% downdraft and you'll not regret it."
Twitter is also filled with complaints, like the one from a user named @Notsofrugaljoey, who wrote: "It's really hard to stomach losing all my hard earned money. Just broke down and cried."
On Reddit, a user in the United Arab Emirates posted a picture of the $100,000 loan he'd taken out in December to buy cryptocurrencies — and that he will now be paying back out of his salary for the next three years.
Mr. Roberts, the British investor who has seen most of his $23,000 vanish, is holding onto his coins in case they turn around. But for now he has stopped trading and is looking for another job.
"I'm living off the little savings I have left still in my bank account," Mr. Roberts said. "I've made a mistake and now I'm going to have to unfortunately pay the cost for the next few years."