What Causes A Stablecoin To Depeg From The Dollar?
A stablecoin is designed to hold steady at one dollar, but “designed to” and “guaranteed to” are different things, and the gap between them is where a depegging event happens.
The short answer
A stablecoin depegs when its market price moves away from its intended dollar value, which can happen because of doubts about whether its reserves are sufficient, a rush of holders trying to redeem or sell at once, a breakdown in the mechanism that’s supposed to keep the price anchored, or a broader loss of confidence that becomes self-reinforcing once it starts. Different stablecoin designs are vulnerable to different combinations of these triggers, but the common thread is that the peg depends on continued trust and functioning mechanics, not on the number one dollar being a fixed property of the token.
Reserve doubts undermine the promise directly
A stablecoin that claims to be fully backed by reserves is only as reliable as those reserves actually being complete, liquid, and available on demand. If credible questions arise about whether the reserves exist as claimed, holders have a rational reason to sell or redeem before others do the same. Even a temporary doubt, later proven unfounded, can trigger enough selling pressure to push the market price below one dollar until confidence and liquidity are restored, which illustrates how the peg is a function of trust as much as of the reserves themselves.
Liquidity crunches make redemption harder in practice
Even a fully backed stablecoin can depeg temporarily if a large number of holders try to redeem or sell at the same time and the mechanism for converting the token back to dollars can’t keep pace with demand. This is a liquidity problem rather than a solvency problem, but from a holder’s perspective in the moment, a stablecoin trading below one dollar looks the same regardless of which underlying cause is responsible.
Mechanism failures affect a different category of stablecoin
Stablecoins that rely on algorithms or other crypto assets as collateral, rather than direct dollar reserves, face an additional risk: the mechanism that’s supposed to maintain the peg can itself fail under stress, particularly when the collateral backing the token is itself volatile and its value falls sharply at the same time redemptions are rising. This is part of why algorithmic and crypto-collateralized designs are generally considered to carry more depegging risk than those backed by overcollateralized reserves with a larger buffer against the same stress, and why some depegging events turn out to be temporary while others raise the more serious question of whether a stablecoin can lose its peg permanently.
Panic and self-reinforcing selling
Even when the underlying cause is minor or resolvable, a depegging event can become self-reinforcing: falling prices attract attention, coverage or social discussion amplifies concern, and more holders decide to sell or redeem before the situation potentially worsens. This dynamic doesn’t require the original concern to be valid, uncertainty alone is often enough to trigger it, and it’s one reason understanding how stablecoin reserves differ from a bank deposit matters for gauging how quickly panic can spread once questions first arise.
The takeaway
A stablecoin’s peg isn’t an intrinsic property of the token, it’s an outcome that depends on reserves, mechanism design, liquidity, and market confidence all holding up simultaneously, and depegging events show what happens when one or more of those supports weakens. Because a stablecoin isn’t covered by FDIC or SIPC protection the way a bank deposit is, understanding which of these risks applies to a specific stablecoin’s design is a meaningful part of evaluating what “stable” actually means in practice.