Stablecoins are the quiet workhorses of crypto: tokens designed to hold a steady value, usually one dollar, so traders can move in and out of volatile assets without leaving the crypto ecosystem. They underpin trading, lending, and payments across decentralised finance. But stable is a design goal, not a guarantee, and several famous stablecoins have lost their pegs, sometimes catastrophically. Understanding how pegs work is essential before holding any of them in size.

The most common design is fiat-backed: each token is backed by reserves of cash and short-term government securities held by the issuer, and users can redeem tokens for dollars. This design is simple and, when reserves are real and audited, relatively robust. Its risks are institutional rather than technical: the reserves may be less liquid or less transparent than claimed, the issuer may be subject to regulatory action, and redemption can be frozen or delayed in a crisis. Trust in the issuer is the peg's foundation.

Crypto-backed stablecoins take a different approach: they are backed by other crypto assets locked as collateral, usually over-collateralised, meaning more collateral value than stablecoins issued. If the collateral's price falls, positions are liquidated to protect the peg. This design is transparent, since collateral sits on-chain, but it is exposed to sharp market falls, where liquidations cascade and collateral value drops faster than the system can sell it. Over-collateralisation is a buffer, not immunity.

Algorithmic stablecoins, which hold their peg through software incentives rather than reserves, are the riskiest design and the one behind the most spectacular failures. They typically pair the stablecoin with a second token that absorbs volatility, expanding and contracting supply to defend the peg. That mechanism works while confidence holds and breaks violently when it does not, because the stabilising token itself collapses in a selling spiral. The 2022 collapse of TerraUSD is the cautionary example every newcomer should know.

Peg breaks, or depegs, usually follow one of three paths. A loss of confidence triggers mass redemptions that exhaust liquid reserves. A market crash overwhelms a crypto-backed system's liquidation capacity. Or a regulatory or banking problem freezes the issuer's reserves, breaking the redemption promise. In each case, the early warning signs are similar: the token trading below its peg on exchanges, redemption delays, and opaque or delayed reserve disclosures. A small, brief deviation is normal; a persistent, widening gap is a signal.

Before trusting a stablecoin, check four things. First, the backing model and whether reserves are independently attested, and how recently. Second, the issuer's jurisdiction and regulatory standing. Third, the token's liquidity and history: has it held its peg through a market crash before? Fourth, your own exposure: holding your entire balance in one stablecoin concentrates issuer risk, while splitting across two well-established options diversifies it. No stablecoin deserves blind trust.

Stablecoins also carry everyday risks beyond depegs. Smart contract bugs can affect crypto-backed designs, bridge hacks can affect wrapped versions on other chains, and regulatory changes can restrict redemption in some regions. Treat stablecoin balances like bank deposits in an unfamiliar bank: useful, but not risk-free, and never assume a dollar token is literally a dollar.

Stablecoins are genuinely useful tools, and the largest fiat-backed options have survived multiple crises. But their safety comes from reserves, transparency, and redemption mechanics, not from the word stable in their name. Check the backing, watch the peg, diversify across issuers, and keep only what you need in any single one.

One more check deserves emphasis: redemption in practice, not just in theory. Some stablecoins promise redemption but impose minimum amounts, long delays, or eligibility restrictions that make redemption impractical for ordinary holders, who must instead sell on an exchange at whatever price the market offers. Test redemption mechanics with a small amount before relying on a stablecoin for a large balance, and prefer issuers whose redemption process is open, fast, and available to ordinary users rather than only to large institutions.