Peg Mechanism

How exactly does the arbitrage redemption mechanism work for fiat-backed stablecoins? Why does it maintain the peg?

The arbitrage redemption mechanism is the core of fiat-backed stablecoin peg mechanics, and it operates very precisely:

When USDC is below $1 (e.g., $0.98) Arbitrageurs can buy 1 USDC in the market for $0.98, then request a 1:1 redemption from Circle for $1 in cash. Each operation profits $0.02. Large numbers of arbitrageurs doing this simultaneously increases market buying demand for USDC → price is pushed back to $1.

When USDC is above $1 (e.g., $1.02) Arbitrageurs can deposit $1 cash with Circle, receive 1 USDC, then sell it in the market for $1.02. Each operation profits $0.02. Large numbers of arbitrageurs simultaneously increasing USDC supply → price is pushed back to $1.

Why this mechanism works: the system's key is that 'the 1:1 redemption guarantee always holds.' As long as Circle's reserves are real and accessible, arbitrage has a certain profit margin and market forces automatically maintain the peg. This also explains why in the 2023 SVB event, the market's concern was 'whether reserves are accessible' rather than 'whether the mechanism is correct' — the mechanism itself was trusted by the market; the problem was reserve liquidity.

Can crypto-backed stablecoins' automated liquidation mechanism function properly during extreme market crashes (like 50% single-day drops)?

This is the most critical stress test question for crypto-backed stablecoins, and the answer is 'it depends on the speed and magnitude of the crash.'

Normal market decline (10-20%): liquidation mechanism works well. Liquidators have sufficient time to identify liquidatable positions, submit transactions, and markets have sufficient liquidity to absorb liquidated collateral.

Rapid crash (30-40% decline within an hour): stress begins to emerge. If blockchain networks become congested (gas fees spike), liquidators may be unable to submit liquidation transactions in time, causing bad debt in the system. The March 2020 MakerDAO Black Thursday crisis was exactly this case.

Extreme crash (50%+ single-day): theoretically, bad debts that liquidation mechanisms can't fully cover may emerge. If all collateral simultaneously depreciates sharply and market liquidity dries up, even over-collateralization may be insufficient. DAI experienced approximately $6 million in system bad debt in March 2020 (covered through MKR token minting).

System improvements: protocols like MakerDAO have continuously optimized liquidation mechanisms after crises (higher collateral ratio requirements, faster liquidation processes, more diversified collateral types) to improve resilience under extreme conditions. But a guarantee of 'zero bad debt can ever occur' doesn't exist in any crypto-backed system.

What role does the Stability Fee play in the peg mechanism of crypto-backed stablecoins?

The Stability Fee is a subtle but important tool for managing the peg in crypto-backed stablecoins like DAI — similar to a central bank's interest rate policy.

Definition of Stability Fee: the annual interest rate users pay when borrowing DAI through MakerDAO. For example, with a 5% Stability Fee, borrowing 1,000 DAI requires repaying 1,050 DAI after one year.

How it helps maintain the peg:

• When DAI is above $1: indicates excessive market demand for DAI, insufficient supply. MakerDAO governance can lower the Stability Fee → reduces borrowing costs → attracts more people to borrow DAI → DAI supply increases → price falls back to $1.
• When DAI is below $1: indicates DAI oversupply or insufficient demand. Governance can raise the Stability Fee → increases borrowing costs → some borrowers choose to repay → DAI supply decreases → price recovers to $1.

Real-world case: in the low-interest-rate environment of 2019-2020, DAI consistently traded slightly above $1 for extended periods, and MakerDAO lowered Stability Fees multiple times (once approaching 0%) to increase DAI supply. This demonstrates the Stability Fee functioning as a monetary policy tool in practice.

Essentially, the Stability Fee is the 'interest rate policy' of crypto-backed stablecoins — except the decision-makers are token holder governance votes, not a central bank committee.

A newly launched stablecoin claims to have an 'innovative peg mechanism' — how should I assess its reliability?

When faced with 'innovative peg mechanism' claims, here's a systematic assessment framework:

Step 1: Find the Worst Case Ignore the white paper's optimistic descriptions. Ask yourself: if market confidence collapses 80% in 24 hours, what does this mechanism rely on to provide liquidity for holders to exit? If the answer is 'relies on others continuing to believe in the system' rather than 'real assets,' that's the highest-risk signal.

Step 2: Reverse-test the mechanism Algorithmic peg maintenance logic typically follows: 'if A occurs, then B incentivizes arbitrage to restore A.' Ask inversely: if A and B both collapse simultaneously (same token, or mutually dependent), what happens? UST's dual-token design had no external stopping force when A (UST) and B (LUNA) collapses reinforced each other.

Step 3: Check stress test records Does this mechanism have a record of functioning normally during large market declines (>30%)? A new mechanism without stress test records doesn't mean it's bad, but it means its actual behavior carries unknown risks.

Step 4: Ask 'what are the real reserves?' If the issuer's claimed reserves are the native token of their own ecosystem, that's not real reserves — under stress, that token and the stablecoin may collapse simultaneously (the triggering condition for a death spiral). Real reserves must be assets external to the stablecoin ecosystem (fiat, Treasuries, other stablecoins).