Depegs, Risks and Regulation: How Stablecoins Break

You’ve now met the whole family: the fiat-backed coins with a vault of dollars, the crypto-backed coins over-collateralized with volatile assets, and the algorithmic coins held together by code and faith. Four lessons of “here’s how it’s supposed to stay at $1.”

This lesson is the other half of the sentence: here’s how it doesn’t. Because “stable” is a goal, not a guarantee — a promise the issuer makes and the market either believes or doesn’t. When the market stops believing, the price wanders. A depeg is exactly that: a stablecoin’s market price drifting meaningfully off its target (for a dollar coin, away from $1). Tiny wobbles to $0.999 or $1.001 are background noise — markets breathe. The real question is whether arbitrage and reserves yank the price back, or whether fear feeds on itself until the thing spirals into the ground.

What a depeg is — temporary vs terminal

A depeg is any meaningful gap between a stablecoin’s market price and its target. But not all depegs are the same animal, and confusing the two is the single most expensive mistake a stablecoin holder can make.

• A temporary (recoverable) depeg is a confidence or liquidity scare. The price dips — sometimes hard — but the underlying value is still there, so once the panic clears, arbitrage and redemptions drag the price back. When it returns to target, we say the coin has repegged.
• A terminal depeg is a break that doesn’t heal: the coin is genuinely insolvent (the backing is gone or never existed) or it’s caught in a self-reinforcing death spiral. The price doesn’t bounce; it goes to zero, or near enough that the difference is academic.

The tell is solvency. Ask: if everyone redeemed right now, is there enough real value behind the coin to pay them at $1? If yes, you’re probably looking at a temporary scare. If no, you’re watching a funeral.

Why pegs break

Pegs don’t break for one reason — they break for a catalog of reasons, and helpfully, each one maps onto a family you already studied. Here are the big five.

1. Reserve doubt / bank run (mainly fiat-backed). The coin is only as good as the dollars behind it — and the dollars are only as good as wherever they’re parked. If the market suspects the reserves aren’t fully there, aren’t high-quality, or can’t be reached, holders rush to redeem before the music stops. A bank run is exactly this: a stampede to get out first, which can break even a solvent issuer if the assets can’t be liquidated fast enough.
2. Collateral crash (mainly crypto-backed). When the backing is volatile crypto, a sharp drop can push vaults underwater — the collateral is suddenly worth less than the coins it minted — faster than liquidations can clear the bad positions. A frozen network or a stale price oracle makes it worse: liquidators can’t act, and bad debt piles up.
3. Liquidity / redemption friction (any family). Even a fully-backed coin depegs on the open market if you can’t redeem fast enough. If only big partners can redeem directly, or redemptions take days, ordinary holders dump on exchanges instead — and a wall of sell orders into thin order books gaps the price down regardless of the reserves.
4. Smart-contract or freeze risk (any on-chain coin). A bug or hack can mint coins from nothing or drain collateral. And the flip side of issuer control: most centralized issuers can freeze addresses or pause transfers — protective against thieves, but a reminder that “your” stablecoin can be made un-spendable.
5. The algorithmic death spiral (algorithmic). The lesson-4 nightmare. When a coin is propped up by minting a sister token, a loss of confidence makes the system mint more and more of that token to defend the peg, crushing its price, which destroys confidence further — a reflexive loop straight to zero. This is the archetypal terminal depeg.

Case study: USDC and Silicon Valley Bank, March 2023

If you want to understand a recoverable depeg, this is the textbook case — and it happened to one of the most conservatively-run stablecoins in existence.

USDC, issued by Circle, is fully fiat-backed: every coin is meant to be matched by a dollar of cash or short-dated US Treasuries. The catch is where the cash lives. In March 2023, Circle held about $3.3 billion of USDC’s cash reserves at Silicon Valley Bank (SVB) — a real, regulated US bank. Over a single weekend, SVB suffered a classic bank run of its own and collapsed.

Now the chain reaction: if $3.3 billion of the reserves were trapped in a failed bank, was USDC still fully backed? Nobody knew yet — and “nobody knew yet” is all a panic needs. USDC holders bolted, dumping on exchanges where redemptions couldn’t keep pace, and the price slid all the way to roughly $0.87–0.88. A “stable” coin, down 12%, in hours.

Then the cavalry: US regulators announced that all SVB depositors would be made whole. Instantly the math flipped — the $3.3 billion was safe, USDC was fully backed after all — and the price climbed back, repegging to $1 within days. The depeg was a confidence scare about reachability, not a solvency hole. The reserves were real the entire time.

The lesson is uncomfortable but vital: even a well-run fiat-backed coin inherits the risk of where it parks the cash. “Fully backed” doesn’t mean “risk-free” — it means the risk has moved from do the dollars exist? to can we reach them right now?

A risk taxonomy

“Is this stablecoin risky?” is the wrong question. The right one is which risks, and how much of each — because the answer depends entirely on the family. Here’s a cross-reference of risk type against the family most exposed to it.

Read it as a portfolio of exposures. A fiat-backed coin trades smart-contract and collateral risk for custodial and censorship risk. A decentralized crypto-backed coin slashes counterparty and freeze risk but loads up on collateral-volatility and smart-contract risk. An algorithmic coin tries to dodge all the backing risks — and inherits the one that kills outright. There is no free lunch; there’s only which risk you’d rather hold.

How to evaluate a stablecoin

You don’t need a forensic accounting degree to size up a stablecoin — you need a checklist and the discipline to actually run it before you hold a cent. Walk these questions, in order:

• What backs it? Cash and short-dated Treasuries are the gold standard. Commercial paper, corporate bonds, long-dated debt, or other crypto are progressively riskier. “Backed by a basket of assets” is a phrase that deserves follow-up questions, not a nod.
• Is it audited, or only attested? An attestation is a point-in-time snapshot — “the reserves existed on the day we looked.” A full audit examines controls and history. Attested-only is weaker; neither is a red flag waving at you.
• Can ordinary users redeem? If only whitelisted partners can swap coins for dollars directly, your only exit in a panic is the open market — exactly where prices gap. Direct, broad redemption is the arbitrage that defends the peg.
• How decentralized / censorable is it? Can the issuer freeze your address? Pause transfers? That’s protection against thieves and a single point of control. Decide which trade-off you want.
• What’s its track record through stress? Has it survived a real crash, a depeg scare, a bank failure? A coin that repegged after SVB has shown its backing. An untested coin is a promise, not a record.
• Where does the yield come from? If a stablecoin pays you a suspiciously juicy yield, something is generating it — lending, leverage, or risk you’re not seeing. As a rule, yield that looks too good to be true is a risk premium in disguise. (And note: under the new US rules below, payment-stablecoin issuers generally can’t pay holders interest at all.)

Regulation

For years stablecoins were too small for governments to bother with. That era is over. Hundreds of billions of dollars now sit in stablecoins, they settle trillions in volume, and they’re effectively private dollars circulating outside the banking system. That’s big enough to matter for financial stability (a sudden run could spill into real markets) and for the dollar itself (these coins extend dollar usage worldwide). So regulators wrote rules. Two frameworks now define the landscape.

The US GENIUS Act

Signed into law on July 18, 2025, the GENIUS Act is the first comprehensive US framework for payment stablecoins. Its core demands on issuers:

• 1:1 reserves, held only in cash, short-dated US Treasuries, and repos backed by them — explicitly no long-dated bonds and no risky assets. The backing has to be safe and liquid.
• Monthly public reserve disclosures, so the market can see the backing without waiting a year.
• Submission to audits and examination — not just self-reported attestations.
• Compliance with AML/BSA rules (anti-money-laundering / Bank Secrecy Act) — the same know-your-customer machinery banks run.
• Issuers generally may not pay interest to holders — keeping the coin a payment instrument, not a deposit substitute.

The EU’s MiCA

The EU’s Markets in Crypto-Assets (MiCA) regulation treats most fiat stablecoins as e-money tokens, requiring:

• 1:1 reserves, with a defined portion held as bank deposits for liquidity.
• Formal issuer authorization — you can’t just deploy a contract and call it a euro.
• Holder redemption rights and disclosure obligations.

The trade-off

Both frameworks buy the same thing: more safety and legitimacy — backing you can verify, issuers you can hold accountable, a coin a regulator stands behind. The price is less permissionless freedom. A coin that demands authorization, audits, KYC, and freeze powers is, by design, less like open infrastructure and more like a regulated bank product. And it leaves the more radical models out in the cold: decentralized and algorithmic stablecoins sit awkwardly with rules that assume a single, authorized, fully-reserved issuer who can freeze addresses on demand. The safest coins under these laws are precisely the least crypto-native ones — which is either the whole point or the whole problem, depending on who you ask.

Key Takeaways

That’s the full picture: you know how stablecoins are built, and now how they break, how to size up the risk, and the rules now shaping them. One thing left — the course final exam. Go prove it.