Death Spiral

How did the UST/Luna death spiral happen? What was the mechanism?

UST's design logic: 1 UST could always be exchanged for $1 worth of Luna, and vice versa. This two-way exchange mechanism was theoretically supposed to maintain UST's peg: if UST fell below $1, arbitrageurs could use discounted UST to redeem equivalent Luna value and sell it, profiting while burning UST to reduce supply, theoretically pushing UST's price back to $1.

The problem was scale and confidence. In early May 2022, a large UST sell-off hit Curve's liquidity pool, causing a minor UST de-peg. Market panic began: large numbers of holders demanded UST redemption → the system minted massive amounts of Luna for redemptions → Luna supply exploded, price dropped → Luna's falling price shrank the value of UST's 'reserve' (Luna) → UST de-pegged further → more people fled → more Luna was minted…

At peak, Luna was being minted at a rate of tens of billions per day, transforming from a multi-dollar token to near-zero value within days. The entire cycle completed in 5 days, with markets accelerating the collapse through every 'self-repair' action the system was designed to take.

Do all algorithmic stablecoins inevitably experience death spirals? Are there any surviving designs?

Not all algorithmic stablecoins inevitably lead to death spirals, but the structural vulnerability in these designs is real.

FRAX (partial collateral): a hybrid design, partially backed by fiat-backed stablecoins like USDC and partially relying on algorithmic mechanisms. By introducing real reserves as a buffer, it has higher collapse resistance than pure algorithmic types. Still operating today, but has faced multiple market stress tests.

DAI (crypto over-collateralized): although commonly categorized as algorithmic, DAI's core is actually over-collateralized crypto assets. Its stability doesn't depend on a dual-token hedging mechanism but on genuine over-collateralization. This is the fundamental reason it has survived multiple market crashes.

The critical dividing line: the highest death spiral risk design is pure algorithmic 'dual-token hedging with no real reserve backing' (like UST). Introducing real reserves or using over-collateralization mechanisms can significantly reduce but not completely eliminate death spiral risk. Before holding any stablecoin claiming algorithmically-maintained pegs, the most important question is: if the peg fails, what provides the backstop?

Once a death spiral begins, is there any way to stop it? What did Terra attempt?

The Terra Foundation did take multiple emergency measures during the UST collapse, but all ultimately failed — this process itself is the best illustration of how difficult a death spiral is to reverse.

Terra Foundation's emergency attempts: First, using Bitcoin reserves (Luna Foundation Guard held approximately $3.5 billion in BTC) to buy UST in the market, attempting to stabilize the price. Second, lending BTC to the market, trying to give market makers capital to maintain UST liquidity. Third, halting the Luna/UST blockchain to stop transactions.

Why all failed: when the market's selling scale far exceeds the reserve's supporting capacity, any single-point intervention is futile. UST's circulating market cap peaked at approximately $18 billion; $3.5 billion in BTC reserves was far insufficient to support a full-scale redemption wave. More importantly, halting the chain actually worsened panic — users couldn't withdraw, and panic amplified.

Lesson for investors: death spirals are self-accelerating by nature; external interventions require scale that often far exceeds any individual organization's capacity. This is why, when evaluating algorithmic stablecoins, 'what provides the backstop when it collapses' matters more than 'how clever the peg-maintaining mechanism is.'

Death spiral risk assessment: how do I judge how dangerous an algorithmic stablecoin is?

Here's a practical risk assessment framework applicable to any stablecoin claiming algorithmically-maintained pegs:

Question 1: What maintains its peg? If the answer is 'another token's minting/burning mechanism' with no external reserves — this is the highest death spiral risk type, similar to UST's dual-token model.

Question 2: Are there real external reserves? Real reserves (cash, Treasuries, other stablecoins) are the last line of defense when the algorithmic mechanism fails. More reserves and higher quality means stronger collapse resistance.

Question 3: What is behavior under extreme stress testing? Look at whether the stablecoin has experienced market crashes historically. FRAX has stress test records from the 2022 bear market; DAI survived multiple crashes. New algorithmic stablecoins without stress test records require extreme caution.

Question 4: What percentage of total circulating supply is your position? If your position size is small relative to the stablecoin's total circulation, you're more likely to find an exit during de-pegging. If you're a large holder, the problem of insufficient liquidity becomes more pronounced during emergency exits.

Combining these four questions, the conclusion is clear: mixed algorithmic types with real reserve backing (like FRAX) carry lower risk; pure dual-token hedging algorithmic types without reserves carry extremely high risk and are unsuitable for any scenario requiring stability guarantees.