Terra's broken peg and the economics of a run
TerraUSD relied on conversion into newly issued Luna to hold its price. When the peg broke, the demand needed to complete that conversion disappeared.
TerraUSD was meant to trade at one US dollar. Its collapse in May 2022 exposed the gap between targeting that price and delivering a dollar to someone who wanted to leave. The mechanism exchanged UST for newly issued units of Luna, a volatile cryptoasset. Keeping the peg therefore depended on more than software executing a conversion: someone ultimately had to be willing to hold the Luna that sellers received.
For companies considering stablecoins as payment or treasury infrastructure, the failure made redemption design a central commercial question. A token could display a steady price through ordinary trading conditions while relying on demand that disappeared during stress. The relevant test was what a business could obtain when it needed to pay wages, settle with a merchant or return a customer's money.
Redemption produced an asset that still needed a buyer
Terra's documentation before the collapse described a sequence of burning the offered coins and minting the requested coins. Oracle exchange rates determined the conversion, with fees and spreads affecting what the trader received. The Bank for International Settlements later explained the intended arbitrage in its June 2022 review: someone buying UST below a dollar could exchange it for newly minted Luna valued at one dollar.
Acquire discounted UST
An arbitrageur buys UST below its intended dollar price.
Burn UST and mint Luna
The market module calculates the conversion using oracle rates, with applicable fees and spreads.
Sell the Luna received
Completing the exit requires buyers and sufficient liquidity at an acceptable price.
Absorb the new supply
Repeated redemptions require the market to absorb further Luna while confidence may be falling.
The intended arbitrage required a buyer for newly issued Luna. Conversion at the protocol's rate did not guarantee a sale at that price. Based on Terra's market specification and the BIS account.
In ordinary conditions, buying discounted UST to perform that exchange could support its market price. But the trader's result depended on selling or valuing the Luna received. A protocol conversion rate could not force a market participant to pay that price. Execution costs, changing prices and the depth of the Luna market therefore sat between the advertised stabilisation mechanism and a completed exit into money usable outside the system.
The response to selling could create more selling
As Luna's price fell, representing a given dollar value required more units of Luna. Redemptions could therefore expand its supply just as confidence in holding it weakened. The BIS described a run in which burning UST produced increasing quantities of Luna and willing buyers disappeared. The mechanism intended to stabilise one token placed additional pressure on the asset expected to absorb its redemptions.
This feedback makes market capitalisation a poor substitute for an executable liquidity estimate. Multiplying a token's latest price by its circulating supply does not show how much money could be raised by selling a large amount of it. The sale itself can change the price. A stress analysis needs to examine the amount offered to actual buyers, the likely price response and the obligations that remain after that response.
Anchor's return was a separate economic promise
The BIS reported that Anchor offered a deposit rate of around 20 percent. That was a rate available through a lending protocol, rather than interest automatically earned by anyone holding UST. Anchor's documentation described a target yield set through governance, supported by borrower interest and staking returns from collateral. When those sources fell short, the design drew on a yield reserve held in UST until it was depleted.
A target return and a stable dollar value were separate promises. The reserve supplemented deposit yield; it did not provide a pool of dollars available to redeem every UST. For a startup attracting deposits through a quoted yield, the important operating questions were who funded the return, how long any support could last and how customer demand would behave if the rate changed.
The same label could conceal different redemption economics
Stablecoin is a description of an intended price behaviour, not a complete account of asset backing or legal rights. A product backed by external reserve assets requires scrutiny of their quality, custody, availability and the holder's redemption rights. A product stabilised through another token requires scrutiny of the market demand and conversion rules supporting that mechanism. Neither inquiry can be replaced by observing a previously steady price.
Terra's specification described the market module's liquidity pools as virtual. A mathematical liquidity parameter did not mean dollars or another external asset were waiting in a bank account. Technical documentation can explain how a swap is calculated while leaving a separate question about what a holder can actually recover under pressure.
Exposure could hide inside a service balance
A payments company might encounter the same token as a settlement asset, customer balance and component of a yield service. Those uses create different obligations, but they do not diversify the underlying price exposure. If customers are promised dollars while the business holds a token worth less, a market movement becomes a funding requirement. The company needs cash or other assets to bridge the difference.
The Federal Reserve later described the Terra run alongside distress across interconnected digital asset businesses in its November 2022 Financial Stability Report. The connections illustrate why exposure needs to be traced beyond direct holdings. A company can avoid owning the failed token yet depend on a provider whose liquidity is affected by it. Contractual service commitments and actual counterparty resources need to be assessed together.
Payment adoption required a credible exit
A merchant accepting a token needs to know what arrives in its bank account, when it arrives and who bears a shortfall along the way. A startup selling the integration must price the cost of conversion, settlement delays and any obligation to make the merchant whole. Attractive nominal transfer fees say little about those costs when the settlement asset itself is unstable.
Terra's collapse showed why payment infrastructure deserves evaluation through a stressed transaction, from customer instruction to usable proceeds. The test is whether the economic and legal arrangements can complete that journey when other holders are leaving too. For venture investors, evidence of that capability is more informative than growth in balances that depends on a subsidised return or confidence in a token's continuing appreciation.
Investment implications
- The Terra mechanism converted UST into Luna valued at roughly one dollar by the protocol; it did not itself deliver a dollar from a cash reserve.
- Anchor's deposit yield supported demand for UST, but its yield reserve and the stablecoin's price mechanism served different purposes.
- Several services can share the same underlying token exposure even when they have different interfaces and operators.
Sources
- III. The future monetary system: The collapse of the TerraUSD stablecoin (opens in a new tab)
Bank for International Settlements
- Market module specification, February 2022 revision (opens in a new tab)
Terra developer documentation
- Anchor Protocol overview (opens in a new tab)
Anchor Protocol; documentation updated March 2022
- Financial Stability Report, November 2022: Funding Risks (opens in a new tab)
Federal Reserve
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