Depeg Mechanics

How it happens

A peg holds because someone can profitably close the gap between the market price and the redemption value, so every peg is only as strong as the redemption right and the arbitrageur's ability to use it. Fiat-backed designs hold reserves at banks and allow par redemption to whitelisted institutions on business days, which leaves the token trading continuously against a redemption channel that is not continuous. Crypto-collateralized designs rely on overcollateralization and timely liquidation, so they fail when collateral gaps through the liquidation threshold faster than auctions can clear. Algorithmic designs with no external collateral rely on a mint-and-burn relationship with a second token, which works only while that token holds value for reasons independent of the peg. Yield-bearing wrappers add another layer, because their price tracks an accrued value rather than the reference itself.

What you can actually observe

Establish who may redeem at par, on what schedule, with what minimum size, and what the reserve is actually invested in, then read the attestation's date and scope. On-chain, look at the depth of the primary trading pair, the collateralization ratio where applicable, and the historical distribution of deviation from the reference rather than only the current price. Past deviations and how quickly they closed are the most informative record a peg has.

Precedent

Terra's UST lost its peg in May 2022 and never recovered because its stabilization mechanism minted a sibling token whose price was collapsing, while USD Coin briefly traded below its reference in March 2023 when part of its reserves sat at a bank that failed and recovered once access to those deposits was assured.

What makes it more or less material

Check what the backing is, who can redeem at par and how quickly, the depth of the main trading pair relative to outstanding supply, and whether the design depends on a second token that it also influences.