What "stable" actually means, and why the word misleads
The word "stablecoin" describes the goal, not the guarantee. Every stablecoin is a token on a blockchain that attempts to track the value of one fiat currency, usually the U.S. dollar. The peg is enforced by some combination of reserves, collateral, smart-contract logic, or arbitrage incentives. None of these mechanisms are infallible, and the differences between them matter enormously when stress hits.
Think of a stablecoin like a claim on a dollar, not a dollar itself. The question is who backs that claim, with what, and how quickly they can honor redemptions when everyone shows up at once. That framing is what separates people who hold stablecoins safely from people who discover the hard way that "stable" was a marketing term.
The stablecoin market today is dominated by a handful of issuers. Tether (USDT) and Circle (USDC) together account for the majority of dollar stablecoin supply, with USDT larger by circulating volume and USDC larger in regulated U.S. institutional use. Decentralized alternatives like DAI and USDe sit alongside them, using different mechanisms but serving similar functions in DeFi trading and lending. Each one has survived different stress tests, and each one has a different breaking point.
The three structural failure modes
Every major stablecoin depeg in history traces back to one of three structural failure modes. Understanding which category a coin falls into tells you what kind of crisis to watch for.
Fiat-backed: the redemption-gate risk
Fiat-backed stablecoins like USDT and USDC hold reserves, ideally cash and short-dated U.S. Treasuries, and issue tokens that represent a claim on those reserves. The peg is maintained by the issuer's promise to redeem tokens at par. When the issuer can no longer honor redemptions quickly, the peg breaks.
The most common trigger is not fraud or insolvency but liquidity. Even a fully solvent issuer can fail to meet redemptions if their banking partners freeze accounts, if redemption queues exceed available cash, or if the underlying assets are in instruments that cannot be sold fast enough. This is the scenario that played out during the March 2023 USDC depeg.
Crypto-backed (CDP): the collateral-liquidation cascade
Crypto-backed stablecoins like DAI rely on over-collateralized debt positions (CDPs), smart contracts where users lock up volatile crypto (usually ETH) and mint stablecoins against it. The peg is maintained by liquidations: if collateral value drops, the system automatically sells collateral to cover debt.
The risk is that during a sharp crypto crash, on-chain liquidation engines can't keep up with falling prices. Oracle delays, gas spikes, and cascading liquidations can push the system under-collateralized. DAI has held its peg through multiple crashes, but smaller CDP systems have depegged under similar pressure.
Algorithmic: the reflexivity death spiral
Algorithmic stablecoins attempt to maintain the peg through mint-and-burn mechanics rather than reserves. The classic example is TerraUSD (UST), which used a sister token (LUNA) to absorb supply and demand imbalances. When UST traded below $1, users could burn UST to mint $1 of LUNA, theoretically reducing UST supply until the peg recovered.
The mechanism works in reverse under stress. As UST depegged in May 2022, more LUNA was minted to absorb the supply, diluting LUNA's value, which reduced confidence in the system's ability to honor the peg, which accelerated UST selling. The reflexivity turned a small deviation into a complete collapse within days.
Case study 1: The May 2022 UST/Terra collapse
UST was the largest algorithmic stablecoin by market cap going into May 2022, with roughly $18 billion in circulation and a sister token (LUNA) valued at over $30 billion. The Anchor Protocol, a lending platform built on Terra, offered around 20% yield on UST deposits, which attracted massive capital but also created a structural fragility: the yield came from emissions, not real lending demand.
On May 7-8, 2022, large UST withdrawals from Curve liquidity pools and selling pressure on Anchor triggered a depeg. UST dropped to $0.98, then $0.70, then below $0.20 over the following week. The mint-and-burn mechanism that was supposed to restore the peg instead hyperinflated LUNA supply. LUNA went from roughly $80 to a fraction of a cent.
Over $40 billion in value was destroyed. The Luna Foundation Guard's reserve fund, intended to defend the peg, was exhausted in days. No bailout was possible because there was no claim on real assets, only a closed-loop token system. This remains the single largest depeg event in crypto history and the definitive proof that purely algorithmic pegs without external collateral are structurally fragile.
Case study 2: The March 2023 USDC depeg
USDC is issued by Circle, a U.S.-regulated company that holds reserves in cash and short-dated Treasuries, audited by a major accounting firm. By all available measures, USDC was one of the safest stablecoins in existence going into March 2023.
Then Silicon Valley Bank (SVB) failed. Circle disclosed that approximately $3.3 billion of its reserves were held at SVB. While the funds were ultimately recoverable (U.S. regulators backstopped SVB depositors), the immediate uncertainty about whether Circle could meet redemptions drove USDC to a low of roughly $0.87 on March 11, 2023.
This depeg illustrates a different risk class: even a fully reserved, compliant issuer is exposed to the banking system's plumbing. USDC holders couldn't redeem directly through Circle in size during the crisis, they had to use on-chain markets, and on-chain markets priced in the uncertainty before the facts were known. USDC recovered to its peg within days once the SVB situation resolved, but for several tense hours, one of the "safest" stablecoins in crypto traded like a distressed asset.
Case study 3: The October 2024 USDe basis-trade unwind
USDe, issued by Ethena Labs, is a "synthetic dollar" that maintains its peg through a delta-neutral basis trade: holding spot crypto (typically ETH) while shorting the equivalent amount via perpetual futures. The funding rate earned from the short leg is passed to holders as yield.
This structure works well when perpetual funding rates are positive, meaning long traders pay shorts. But when funding rates turn negative, the trade becomes unprofitable. In early October 2024, a sharp crypto market move and a crowded basis trade triggered a cascade. USDe briefly traded below $0.65 on some venues as holders rushed to exit, and liquidity in the ETH spot and perp markets thinned.
The USDe episode demonstrates a fourth risk vector: derivatives-driven unwinds. Even when reserves are intact and smart contracts work as designed, the market structure that produces the yield can become a liquidity sink. Basis trades unwind in both directions, and a crowded position can amplify any directional move.
Risks to understand before holding any stablecoin
Redemption-gate and liquidity-cascade risk
Every stablecoin has some upper limit on how fast it can honor redemptions. For fiat-backed coins, that limit is set by banking hours, wire transfer cutoffs, and the liquidity of the reserve assets. For crypto-backed coins, it's set by on-chain liquidation capacity and oracle responsiveness. For algorithmic coins, there's no real redemption, only arbitrage.
During a crisis, holders race to be first. If too many people try to exit at once, the peg breaks before the mechanism can respond. This is the fundamental reason depegs are self-fulfilling: the fear of a depeg causes the depeg.
Counterparty and custodian risk
Fiat-backed stablecoins depend on the solvency and operational reliability of their banking partners and custodians. If a custodian fails or restricts withdrawals, the issuer can't honor redemptions even if the reserves are technically there. The USDC/SVB episode showed this clearly.
Smart-contract and oracle risk
Crypto-backed and algorithmic stablecoins depend on smart contracts that can contain bugs and oracles that can report incorrect prices. A single oracle manipulation or contract exploit can break the peg or drain collateral.
Regulatory risk
Stablecoins sit in a regulatory gray area in many jurisdictions. A sudden enforcement action, a sanction, or a freeze on a specific issuer can cause a localized depeg even if the underlying mechanism is sound.
How depegs become self-fulfilling
The most counterintuitive feature of stablecoin depegs is that confidence is the product. When holders believe a coin will hold its peg, they hold, and the peg holds. When holders believe it might break, they sell, and the peg breaks.
This reflexivity is why depegs tend to accelerate once they start. Early signs of stress attract attention, attention attracts sellers, sellers create price pressure, price pressure confirms the fear, and the cycle repeats. By the time the underlying issuer or mechanism responds, the peg may have already broken.
The implication is that monitoring stablecoin health is not about reading reserve attestations after the fact. It's about watching real-time signals: liquidity pool imbalances, redemption queue lengths, basis trade funding rates, and the velocity of on-chain transfers. These are leading indicators that tell you whether confidence is holding before the peg actually moves.
How to hold stablecoins more safely
No stablecoin is risk-free, but some risk-reduction strategies are available to DeFi users and treasury teams.
Diversify across mechanisms. Holding all your stablecoins in one issuer exposes you to that issuer's specific failure mode. A mix of fiat-backed (USDC), crypto-backed (DAI), and even cash equivalents reduces correlated risk.
Watch the peg, not the brand. Check actual on-chain liquidity and secondary-market prices rather than relying on the issuer's stated backing. Tools that track Curve, Balancer, and other stablecoin pools can show real-time peg pressure.
Understand the yield source. If a stablecoin offers unusually high yield, ask where the yield comes from. Anchor's 20% came from emissions; Ethena's yield comes from basis trades. Both carry risk that the yield implies.
Keep an exit plan. Know how you would move out of a stablecoin position if the peg started to slip. Pre-positioned hedges, diversified venues, and held cash reserves outside crypto can reduce forced-selling risk.
How to follow stablecoin depeg risk the smart way
Stablecoin depegs are rare but consequential, and the warning signs appear in on-chain data, liquidity pool balances, and news velocity before they appear in price. Tracking those signals manually across a dozen pools, exchanges, and news feeds is impractical for most users. Zippfeed surfaces stablecoin headlines with sentiment scoring (bullish, neutral, or bearish) and an importance rating, so you can spot stress early and act before a depeg becomes a loss.
