A stablecoin is designed to maintain a fixed value, such as $1.00 USD. This fixed exchange rate is known as the “peg.” When the market price of the token deviates significantly from this target, the event is called a “de-pegging.” This is the most critical failure mode for any stablecoin system.
While de-pegging can happen for many reasons, it is almost always a result of a loss of market confidence. Once users stop believing that a token can be redeemed for its target value, they begin to sell. This selling pressure can overwhelm the system’s stabilization mechanisms, leading to a rapid collapse in price.
The role of market liquidity
The primary defense against de-pegging is liquidity. Liquidity is the ability to trade an asset quickly and without causing a major price change.
The digital asset bank run
In a traditional bank run, depositors rush to withdraw their cash all at once. If the bank does not have enough physical cash on hand, it fails. A stablecoin face a similar risk. If a large number of users suddenly want to exit their positions, there must be enough “buy” orders in the market to absorb the selling pressure.
If the market lacks sufficient liquidity, even a small amount of selling can cause the price to dip below $1.00. This dip can trigger panic among other holders, who then rush to sell their tokens before the price falls further. This feedback loop is the standard mechanism for a de-pegging event.
Exhaustion of the “arbitrage” mechanism
Stablecoins rely on arbitrageurs to maintain the peg. If a token’s price falls to $0.99, an arbitrageur can buy it and redeem it with the issuer for $1.00, pocketing a 1% profit. This buying pressure should, in theory, push the price back up to $1.00.
However, if the arbitrageurs lose confidence in the issuer’s ability to process redemptions, they will stop buying. Without the support of these market participants, the peg has no mechanism to recover, and the price will continue to drift downward based on market sentiment.
Failure of the collateral model
Most stablecoins are backed by other assets. If the value of those underlying assets falls too low, the stablecoin becomes “under-collateralized.”
Devaluation of volatile assets
In crypto-collateralized models, the system uses assets like Ethereum to back the stablecoin. Because these assets are volatile, the system requires “over-collateralization”—holding $1.50 in Ethereum for every $1.00 of stablecoin issued.
If the price of Ethereum crashes faster than the system can liquidate the collateral, the total value of the backing may fall below the value of the tokens in circulation. Once the market realizes the stablecoin is no longer fully backed, a de-pegging event becomes likely. This risk is highest during broad market crashes where all digital assets are falling simultaneously.
Impairment of fiat reserves
For fiat-backed stablecoins, the risk is that the cash or bonds held in the bank lose value or become inaccessible. As discussed in our analysis of stablecoin risks, a bank failure can freeze an issuer’s reserves.
If the market learns that a portion of the reserves is missing or tied up in legal proceedings, the “implied value” of the token drops. Even if most of the reserves are safe, the uncertainty about the remaining portion is often enough to drive the price below the peg as users seek to avoid even a small potential loss.
Technical and algorithmic flaws
Some stablecoins do not use traditional collateral. Instead, they use complex mathematical formulas to manage the supply and demand of the token.
The “death spiral” of algorithmic models
Algorithmic stablecoins often use a secondary “governance” token as a shock absorber. If the stablecoin price falls, the system mints more governance tokens to buy and burn the stablecoin, reducing supply.
This model depends on the governance token having a high enough market value to support the stablecoin. If both tokens fall in price at the same time, the system must mint more and more governance tokens, which further crashes their price. This leads to a “death spiral” where the entire system collapses toward zero. The most famous example of this was the collapse of the TerraUSD (UST) system in 2022.
Smart contract exploits
A technical bug in the code that governs the stablecoin can also cause a de-pegging event. If an attacker finds a way to mint tokens without providing collateral, they can “dump” those tokens on the market.
This sudden influx of supply, combined with the loss of trust in the system’s security, almost always leads to a rapid collapse. Unlike a liquidity issue, which can sometimes be fixed over time, a technical exploit often results in a permanent loss of value for the token holders.
Contagion and market psychology
Stablecoins do not exist in a vacuum. They are part of a deeply interconnected financial ecosystem.
The cascade effect
Many decentralized finance protocols use stablecoins as their primary “building block.” If one major stablecoin loses its peg, it can cause problems for other platforms that hold it as collateral. This can trigger a cascade of liquidations and failures across the entire industry.
This fear of “contagion” can cause users to exit even healthy stablecoins if they believe the wider market is in trouble. Psychology plays a massive role in maintaining a peg; a stablecoin is only “stable” as long as the majority of the market believes everyone else will treat it as such.
Regulatory and legal triggers
News of a government investigation or a change in regulation can also trigger a de-pegging. If a regulator orders a major issuer to stop minting or to freeze its reserves, the market will react instantly.
Even the possibility of a major regulatory crackdown can lead to an “exit rush” where users move their funds into physical cash or other digital assets. This rush can overwhelm the available liquidity and cause a de-pegging event, even if the issuer has done nothing wrong.
Summary of de-pegging risks
While stablecoins are designed to be safe havens, they are subject to the same laws of supply, demand, and confidence as any other asset. A de-pegging is rarely caused by a single factor. Instead, it is usually a combination of declining collateral value, insufficient market liquidity, and a sudden spark of panic.
Understanding how stablecoin issuance works can help users evaluate the strength of a token’s stabilizing mechanism. However, as history has shown, no system is entirely immune to the risks of a fast-moving digital market.
