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The collapse of / in May 2022 is the single most spectacular failure in crypto history. Not a hack, not an exchange collapse — a design failure. The stablecoin was never stable. The $40 billion that evaporated in 72 hours was real money from real people who believed a 20% yield was safe. It is the definitive cautionary tale about and the danger of confusing “it has worked so far” with “it is sound.”
The idea: a stablecoin without reserves
Most stablecoins maintain their dollar peg by holding actual dollar reserves — bank deposits, Treasury bills, etc. The idea behind Terra's UST was different and, in theory, elegant: UST would maintain its peg through an algorithm that minted and burned , Terra's native token.
The mechanism worked like this: you could always burn 1 UST to mint $1 worth of Luna, and burn $1 worth of Luna to mint 1 UST. If UST traded above $1, arbitrageurs would mint UST (increasing supply) and sell it, pushing the price down. If UST traded below $1, arbitrageurs would buy UST, burn it, and receive $1 of Luna — reducing UST supply and pushing the price back up.
The peg, in other words, was backed not by dollars but by the market value of Luna. As long as Luna had value, the algorithm could defend UST. This is the core idea behind all algorithmic stablecoins — and the reason they are all, at their root, fragile.
The algorithmic mechanism has a death-spiral failure mode. If UST falls below $1 and people burn UST for Luna, the supply of Luna increases. If enough people do this, Luna's price falls (more supply, same demand). As Luna's price falls, more Luna must be minted to absorb each dollar of UST selling — which increases Luna supply further, which pushes Luna's price down further. The system is stable when demand for Luna is growing, and catastrophically unstable when it isn't. The “backing” for UST is the market cap of Luna — and a market cap is not a guaranteed redemption value.
Anchor: the 20% magnet
The algorithm alone wouldn't have attracted $18 billion in UST. What pulled the money in was Anchor Protocol, a lending market on Terra that offered approximately 20% APY on UST deposits. Where did 20% come from? Not from borrowers paying 20% — there were never enough real borrowers. The yield was subsidized by Terraform Labs and by the protocol's own reserve, essentially paying depositors with token inflation and treasury funds.
This was, in substance, a customer acquisition cost. Terraform Labs was paying 20% to attract UST deposits, because UST adoption made the Terra ecosystem more valuable, which made Luna more valuable, which made the peg more robust — a circular logic that works on the way up and destroys itself on the way down.
Retail investors treated Anchor's 20% as “safe yield” — comparable to a savings account. It was not a savings account. It was a subsidy dependent on Luna's continued strength. When that strength broke, the yield and the principal both vanished.
The Luna Foundation Guard
To his credit, Do Kwon recognised the death-spiral risk. In early 2022, he established the Luna Foundation Guard (LFG), a reserve that accumulated approximately $3 billion in Bitcoin and other assets, to be used to defend UST's peg if the algorithm failed. The idea was that LFG would buy UST with BTC if UST de-pegged, absorbing the selling pressure.
The LFG reserve was a good idea that proved insufficient. When the attack came in May 2022, LFG deployed its reserves — but the selling pressure overwhelmed them in hours. $3 billion sounds like a lot, but the death spiral's selling pressure was uncapped: every UST burned minted more Luna, which crashed Luna further, which made the next UST burn mint even more Luna. No finite reserve can defend against a self-reinforcing hyperinflationary spiral once it starts.
The attack: May 7–14, 2022
On May 7, 2022, roughly $1.5 billion in UST was pulled out of Anchor and sold on Curve Finance's UST liquidity pool. The event is often described as a single attacker borrowing UST and dumping it — but that theory is contested: on-chain forensics attributed the selling to several wallets, and some academic analyses read the run as decentralized panic rather than a concentrated attack. Either way, the selling pushed UST below $1 and triggered the algorithmic defense: Luna began minting at an accelerated rate to absorb the UST being sold.
For the first day, this looked like a temporary de-peg — UST had wobbled before. But by May 9, UST was at $0.90 and falling. LFG deployed its Bitcoin reserves to buy UST, but the selling pressure was relentless. By May 10, UST was at $0.80 and Luna was plunging.
Then the death spiral kicked in fully. As UST burned into Luna, Luna's supply exploded. Luna's price, which had been around $60 on May 9, fell to $1 by May 12 and to fractions of a cent by May 14. The hyperinflation was so extreme that Cosmos-based validators paused the Terra chain to try to stop the minting — but it was too late. UST settled around $0.20–0.30, and Luna was effectively worth zero.
The entire collapse — from a stablecoin at $1 to a stablecoin at $0.20 and a $40 billion token at zero — took approximately 72 hours for the acute phase, with the full unraveling stretching across about a week.
The timeline
Tap any event to expand its story.
Do Hyeong Kwon (Do Kwon) and Daniel Shin found Terraform Labs in South Korea. The vision: a blockchain payments network anchored by a stablecoin that maintains its peg algorithmically — no dollar reserves required.
Anchor Protocol goes live on Terra mainnet in March 2021 (its whitepaper had appeared in 2020), offering a ~20% APY on UST deposits. The yield is topped up by a reserve funded in UST — largely by Terraform Labs directly. This 20% becomes the magnet that pulls billions into the ecosystem.
As the crypto bull market intensifies and Anchor's 20% yield attracts capital, UST supply grows from under $200M to nearly $10 billion. Luna's price rises in tandem, reinforcing the system's apparent strength.
Luna's market cap peaks near $40 billion; combined with UST and other Terra ecosystem tokens, the total value associated with Terra exceeds $60 billion. Do Kwon becomes a billionaire and a polarising public figure, taunting critics on Twitter.
About $1.5 billion in UST is withdrawn from Anchor and sold on Curve Finance's UST-3pool liquidity pool, pushing UST below $1. One widely reported theory blames a single attacker; on-chain forensics attributed the selling to several wallets. The pool's imbalance triggers the algorithmic mechanism: Luna begins minting hyper-inflationary to defend the peg.
UST falls to $0.90, then $0.80. The Luna Foundation Guard (LFG) — a reserve Do Kwon had built to defend the peg — deploys ~$1.5 billion in Bitcoin reserves to buy UST, but it is not enough. Panic accelerates.
As UST falls further, the algorithm mints more Luna to absorb the selling. Luna's price collapses from ~$60 to under $1 in 48 hours. The hyperinflation of Luna destroys confidence in the system that was supposed to back UST, which falls to $0.30. The death spiral is now self-reinforcing.
Luna falls to fractions of a cent. Exchanges delist it. UST stabilises around $0.20–0.30, far below peg. An estimated $40+ billion in value has evaporated in under a week — the acute phase lasting roughly 72 hours. Thousands of retail investors who had put savings into Anchor's "safe 20%" lose everything.
The SEC files fraud charges against Terraform Labs and Do Kwon, alleging a "massive crypto fraud" involving the unregistered sale of securities and false claims about UST's stability.
Do Kwon is arrested at Montenegro's Podgorica airport attempting to fly to Dubai with forged travel documents. Both the US and South Korea request his extradition. He is extradited to the US on December 31, 2024 to face fraud charges.
The aftermath
The human cost was enormous. Anchor's 20% yield had attracted retail savers from Korea, Eastern Europe, Southeast Asia, and Latin America — many of whom had deposited life savings, retirement funds, or mortgage money. Social media filled with stories of people who had lost everything. The “safe 20%” framing was, in retrospect, a catastrophic misrepresentation of risk.
The legal aftermath unfolded over years. In February 2023, the SEC charged Terraform Labs and Do Kwon with a “massive crypto fraud”. Do Kwon went on the run, living in Serbia and Montenegro before being arrested at Podgorica airport in March 2023 with forged travel documents. After a lengthy extradition battle, he was extradited to the US on December 31, 2024 to face fraud charges. In April 2024, a US civil jury found Terraform Labs and Do Kwon liable for defrauding investors; in June 2024, Terraform agreed to pay roughly $4.47 billion in SEC settlements and to wind down its operations. In August 2025, Do Kwon pleaded guilty to two fraud charges in the US criminal case.
The Terra collapse also triggered a cascade. Three Arrows Capital (3AC), a major crypto hedge fund with heavy Luna exposure, collapsed in June 2022. Lenders Celsius and BlockFi, which had lent to 3AC, followed. The contagion weakened firms across the industry as November 2022 arrived — though FTX's own collapse that month stemmed from its misuse of customer funds — setting up the next catastrophe in our FTX deep dive.
Algorithmic stablecoins — stablecoins backed by the market value of a volatile token — are not stable. They work during bull markets (when the backing token is rising) and fail catastrophically during stress (when the death spiral activates). The Terra collapse was not a black swan; it was the predictable failure of a design with a known death-spiral failure mode. The lesson is not “this particular algorithm was bad” — it is that no algorithmic stablecoin can credibly promise stability under stress, because the backing asset is inherently volatile. If you want a stablecoin that survives a bank run, the reserves must be liquid and low-volatility at par — T-bills, not tokens.
Key takeaways
- Terra's UST was an algorithmic stablecoin: its peg was backed by the market value of Luna, not by dollar reserves. This design has a death-spiral failure mode that is inherently unstable under stress.
- Anchor Protocol's ~20% APY was the magnet that attracted $18+ billion in UST. The yield was subsidized, not earned from real borrowers — it was a customer acquisition cost, not a savings rate.
- In May 2022, a large sell order triggered the death spiral. Luna hyperinflated to zero in ~72 hours; UST fell to $0.20. An estimated $40+ billion evaporated. The Luna Foundation Guard's $3B Bitcoin reserve could not stop a self-reinforcing spiral.
- Do Kwon was arrested in March 2023 and extradited to the US to face fraud charges. The SEC charged Terraform Labs with a “massive crypto fraud.”
- The Terra collapse triggered a contagion (3AC, Celsius, BlockFi, FTX) that defined the 2022 crypto winter. For the comparison with reserve-backed stablecoins, see Stablecoin Wars.