Do Kwon, a trash-talking entrepreneur from South Korea, known as the cryptocurrency he created in 2018 “my biggest invention.” In numerous tweets and interviews, he trumpeted the world-changing potential of the forex, Luna, rallying a band of buyers and supporters he proudly known as “Lunatics.”

Mr. Kwon’s firm, Terraform Labs, raised greater than $200 million from investment firms akin to Lightspeed Enterprise Companions and Galaxy Digital to fund crypto tasks constructed with the forex, at the same time as critics questioned its technological underpinnings. Luna’s whole worth ballooned to greater than $40 billion, making a frenzy of pleasure that swept up day merchants and start-up founders, in addition to rich buyers.

Mr. Kwon dismissed issues with a taunt: “I don’t debate the poor.”

However final week, Luna and one other forex that Mr. Kwon developed, TerraUSD, suffered a spectacular collapse. Their meltdowns had a domino impact on the remainder of the cryptocurrency market, tanking the worth of Bitcoin and accelerating the lack of $300 billion in worth throughout the crypto economic system. This week, the worth of Luna remained near zero, whereas TerraUSD continued to slip.

The downfall of Luna and TerraUSD presents a case research in crypto hype and who’s left holding the bag when all of it comes crashing down. Mr. Kwon’s rise was enabled by revered financiers who have been prepared to again extremely speculative monetary merchandise. A few of these buyers bought their Luna and TerraUSD cash early, reaping substantial earnings, whereas retail merchants now grapple with devastating losses.

Pantera Capital, a hedge fund that invested in Mr. Kwon’s efforts, made a revenue of about 100 instances its preliminary funding, after promoting roughly 80 % of its holdings of Luna during the last 12 months, mentioned Paul Veradittakit, an investor on the agency.

Pantera turned $1.7 million into round $170 million. The latest crash was “unlucky,” Mr. Veradittakit mentioned. “Loads of retail buyers have misplaced cash. I’m certain lots of institutional buyers have, too.”

Mr. Kwon didn’t reply to messages. Most of his different buyers declined to remark.

Kathleen Breitman, a founding father of the crypto platform Tezos, mentioned the rise and fall of Luna and TerraUSD have been pushed by the irresponsible habits of the establishments backing Mr. Kwon. “You’ve seen a bunch of individuals making an attempt to commerce of their reputations to make fast bucks,” she mentioned. Now, she mentioned, “they’re making an attempt to console people who find themselves seeing their life financial savings slip out from beneath them. There’s no protection for that.”

Mr. Kwon, a 30-year-old graduate of Stanford College, based Terraform Labs in 2018 after stints as a software program engineer at Microsoft and Apple. (He had a accomplice, Daniel Shin, who later left the corporate.) His firm claimed it was making a “modern financial system” wherein customers may conduct difficult transactions with out counting on banks or different middlemen.

Mr. Shin and Mr. Kwon started advertising and marketing the Luna forex in 2018. In 2020, Terraform started offering TerraUSD, which is called a stablecoin, a sort of cryptocurrency designed to function a dependable technique of change. Stablecoins are sometimes pegged to a steady asset just like the U.S. greenback and will not be purported to fluctuate in worth like different cryptocurrencies. Merchants typically use stablecoins to purchase and promote different riskier property.

However TerraUSD was dangerous even by the requirements of experimental crypto know-how. Not like the favored stablecoin Tether, it was not backed by money, treasuries or different conventional property. As an alternative, it derived its supposed stability from algorithms that linked its worth to Luna. Mr. Kwon used the 2 associated cash as the premise for more elaborate borrowing and lending projects within the murky world of decentralized finance, or DeFi.

From the start, crypto consultants have been skeptical that an algorithm would hold Mr. Kwon’s twin cryptocurrencies steady. In 2018, a white paper outlining the stablecoin proposal reached the desk of Cyrus Younessi, an analyst for the crypto funding agency Scalar Capital. Mr. Younessi despatched a be aware to his boss, explaining that the mission may enter a “demise spiral” wherein a crash in Luna’s worth would carry the stablecoin down with it.

“I used to be like, ‘That is loopy,’” he mentioned in an interview. “This clearly doesn’t work.”

As Luna caught on, the naysayers grew louder. Charles Cascarilla, a founding father of Paxos, a blockchain firm that provides a competing stablecoin, cast doubt on Luna’s underlying know-how in an interview final 12 months. (Mr. Kwon responded by taunting him on Twitter: “Wtf is Paxos.”) Kevin Zhou, a hedge fund supervisor, repeatedly predicted that the 2 currencies would crash.

However enterprise funding got here pouring in anyway to fund tasks constructed on Luna’s underlying know-how, like providers for individuals to change cryptocurrencies or borrow and lend TerraUSD. Buyers together with Arrington Capital and Coinbase Ventures shoveled in additional than $200 million between 2018 and 2021, in keeping with PitchBook, which tracks funding.

In April, Luna’s worth rose to a peak of $116 from lower than $1 in early 2021, minting a generation of crypto millionaires. A neighborhood of retail merchants fashioned across the coin, hailing Mr. Kwon as a cult hero. Mike Novogratz, chief government of Galaxy Digital, which invested in Terraform Labs, introduced his assist by getting a Luna-themed tattoo.

Mr. Kwon, who operates out of South Korea and Singapore, gloated on social media. In April, he introduced that he had named his newborn daughter Luna, tweeting, “My dearest creation named after my biggest invention.”

“It’s the cult of character — the bombastic, boastful, Do Kwon angle — that sucks individuals in,” mentioned Brad Nickel, who hosts the cryptocurrency podcast “Mission: DeFi.”

Earlier this 12 months, a nonprofit that Mr. Kwon additionally runs sold $1 billion of Luna to investors, utilizing the proceeds to purchase a stockpile of Bitcoin — a reserve designed to maintain the worth of TerraUSD steady if the markets ever dipped.

Across the similar time, a few of the enterprise capital corporations that had backed Mr. Kwon began to have issues. Hack VC, a enterprise agency centered on crypto, bought its Luna tokens in December, partly as a result of “we felt the market was due for a broader pullback,” mentioned Ed Roman, a managing director on the agency.

Martin Baumann, a founding father of the Hong Kong-based enterprise agency CMCC International, mentioned his firm bought its holdings in March, at about $100 per coin. “We had gotten growing issues,” he mentioned in an e-mail, “each from tech facet in addition to regulatory facet.” (CMCC and Hack VC declined to touch upon their earnings.)

Even Mr. Kwon alluded to the potential for a crypto collapse, publicly joking that some crypto ventures would possibly in the end go beneath. He mentioned he discovered it “entertaining” to observe firms crumble.

Final week, falling crypto costs and difficult financial traits mixed to create a panic within the markets. The value of Luna fell to just about zero. As critics had predicted, the worth of TerraUSD crashed in tandem, dropping from its $1 peg to as little as 11 cents this week. In a matter of days, the crypto ecosystem Mr. Kwon had constructed was basically nugatory.

“I’m heartbroken in regards to the ache my invention has introduced on all of you,” he tweeted final week.

A few of Mr. Kwon’s main buyers have misplaced cash. Changpeng Zhao, chief government of the crypto change Binance, which invested in Terraform Labs, said his agency had purchased $3 million of Luna, which grew to a peak worth of $1.6 billion. However Binance by no means bought its tokens. Its Luna holdings are at present value lower than $3,000.

That loss remains to be solely a drop within the bucket for an organization as massive as Binance, whose U.S. arm is valued at $4.5 billion.

“Many of the V.C.s have the analysts they should assess this stuff,” Mr. Nickel mentioned. “They might have figured they might money out on the backs of retail.”

A lot of the ache of the collapse has as a substitute been felt by common merchants. On a Reddit forum for Luna evangelists, customers shared lists of suicide hotlines, as individuals who had poured their financial savings into Luna or TerraUSD expressed despair.

The crash has additionally devastated the fans who have been constructing start-ups that used the crypto infrastructure developed by Mr. Kwon.

Neel Somani, 24, give up his job as a quantitative researcher at Citadel, a hedge fund, in February to work on a project that related Luna’s underlying blockchain to Ethereum, one other crypto system.

In April, Mr. Somani joined Terra Hacker House, a monthlong program in a Chicago workplace sponsored by Terraform Labs and its buyers, designed to incubate tasks constructed on Mr. Kwon’s know-how. Inside a couple of weeks, Mr. Somani lined up $10 million in commitments for enterprise funding that valued his mission, Terranova, at $65 million. He was near hiring three workers, he mentioned, and had 40 prospects excited in regards to the concept.

After Luna and TerraUSD tumbled, Mr. Somani and his fellow hackers initially thought Mr. Kwon and his companions may flip issues round. However by final Tuesday, Mr. Somani realized it was over, and felt relieved he hadn’t but accepted the funding. He misplaced round $20,000 of Luna, he mentioned, which didn’t trouble him since he has made cash on different dangerous inventory and crypto bets.

Over the past week, the desks on the hacker home have emptied. A Telegram group known as Rebuilding Terra, with almost 200 members, has been actively discussing the way to salvage tasks and funds.

Mr. Somani is sanguine. “For these of us who’re crypto builders, the feast and famine mentality comes actually naturally, and that’s possibly what attracted us to the neighborhood,” he mentioned.

On Thursday, he plans to pitch his now-obsolete know-how on the hacker home’s demo day. Most different teams have left this system, he mentioned, so he expects much less competitors for a $50,000 first-place prize.

“It’s in U.S. {dollars},” he mentioned. “I requested.”

Kirsten Noyes contributed analysis.