What specifically happens after the collateralization ratio falls below the liquidation line? How much will I lose?
When your position's collateralization ratio falls below the liquidation line, the protocol's liquidation mechanism automatically activates, typically as follows:
Step 1: Liquidators intervene. The protocol allows any third-party 'liquidator' holding stablecoins to purchase your collateral at a discounted price while repaying part or all of your debt. This discount is typically 5-15%, used to incentivize liquidators to act quickly.
Step 2: Your position is force-closed. Your collateral is sold, your borrowed stablecoin debt is repaid, and remaining collateral (after liquidation penalties) is returned to you.
Your actual loss: Suppose you deposited $150 of ETH and borrowed 100 DAI. When ETH falls and triggers liquidation, liquidators buy some ETH at ~90% discount to repay the DAI debt. Beyond the paper loss from ETH's price drop, you additionally pay approximately 10% in liquidation penalties. Total losses are typically 5-10% more than 'manually closing the position near the liquidation line.'
Conclusion: the core purpose of collateralization ratio management is to have sufficient time to add collateral or partially repay before hitting the liquidation line, avoiding unnecessary liquidation penalties.
Why do crypto-backed stablecoins require over-collateralization? Isn't 150% a wasteful use of capital?
Yes, from a pure capital efficiency perspective, over-collateralization is indeed a form of 'waste.' Depositing $150 of ETH to borrow only 100 DAI means $50 of capital isn't being fully utilized. This is the biggest competitive disadvantage of crypto-backed stablecoins compared to fiat-backed types.
But the reason for over-collateralization is fundamental: the high volatility of crypto assets. ETH can fall 20-30% in a single day. If only 100% collateralization were allowed (borrowing stablecoins equal to collateral value), any slight price drop would leave collateral insufficient to cover debt, and the entire system would collapse with every market move.
The buffer provided by over-collateralization gives the system sufficient time to notify and execute liquidations as assets fall, ensuring debt can be fully covered even in rapidly declining markets.
An interesting contrast: fiat-backed stablecoins like USDC can operate at 100% collateralization because USD doesn't fall 30% in a day like ETH. Stablecoin design fundamentally trades capital efficiency for safety buffer — the required collateralization ratio reflects the underlying asset's volatility.
How do you choose an appropriate collateralization ratio? What are the problems with setting it too high or too low?
This is the most core practical question for using crypto-backed stablecoins (like borrowing DAI on MakerDAO).
Problems with setting too low (near liquidation line): high capital efficiency but high risk. If ETH drops 20-30% faster than you can react, the position may be liquidated before you realize, paying additional liquidation penalties. Suitable for: advanced users who can monitor positions at any time and have deep market judgment.
Problems with setting too high (like 300%+): very safe, but extremely low fund utilization. Depositing large amounts of ETH to borrow only a small amount of DAI — if your purpose is just to borrow a little liquidity, an excessively high collateralization ratio means you've locked up too much capital.
General practical recommendation: for high-volatility assets like ETH, maintaining a 170-200% collateralization ratio is advisable. This provides ample buffer space (ETH needs to fall 40-50% before hitting the liquidation line) while keeping fund efficiency reasonable. During high-volatility market periods (large negative news events), consider proactively raising your collateralization ratio or partially repaying.
What happened with crypto-backed stablecoin collateralization ratio management on March 2020 (Black Thursday)? What does this event illustrate?
March 12, 2020 was one of the most important stress tests in crypto-backed stablecoin history.
What happened: ETH fell more than 50% in a few hours that day, causing a massive number of MakerDAO positions to hit their liquidation lines almost simultaneously. Due to Ethereum network congestion and spiking gas fees, the normal liquidation process was severely delayed — liquidators couldn't submit transactions in time. Some liquidation bots even won auctions for millions of dollars worth of ETH collateral with 0 DAI bids, because no competitors could submit bids in time. This event ultimately resulted in approximately $6 million in bad debt for the MakerDAO system.
The key issues this event illustrates: the over-collateralization safety buffer can fail under the dual pressure of extreme market conditions and on-chain infrastructure congestion. The collateralization ratio design itself is sound, but execution-layer factors (gas fees, network speed) are also part of the overall system's safety.
Post-event improvements: MakerDAO subsequently introduced improved auction mechanisms, adjusted liquidation penalty parameters, and later the multi-collateral DAI design, reducing the risk of similar events recurring. But this case remains a constant reminder: every system has unknown vulnerabilities before stress testing.
A concrete numerical calculation illustrating practical collateralization ratio management.
Scenario Setup
Xiao Wang holds 3 ETH, currently priced at $2,000 each, total value $6,000. He wants to borrow DAI from MakerDAO (Sky Protocol) for short-term expenses without selling his ETH.
He deposits 3 ETH ($6,000) and decides to borrow $3,000 DAI
Initial collateralization ratio: $6,000 ÷ $3,000 × 100% = 200% (well above liquidation line — safe)
Scenario 1: ETH drops 20% (from $2,000 to $1,600 each)
Scenario 2: ETH continues falling to $1,100 each
How to avoid liquidation? Xiao Wang has two options: (1) Add more ETH collateral to increase collateral value (e.g., add 1 more ETH, raising the ratio from 110% back to 147%). (2) Partially repay DAI (e.g., repay 1,000 DAI, reducing debt to $2,000, raising the ratio from 110% back to 165%).
Core lesson: Setting an initial 200% collateralization ratio means ETH needs to fall 45% before hitting the liquidation line (from $2,000 to $1,100). This buffer gives Xiao Wang sufficient time to take action as markets fall, rather than being suddenly liquidated.
The core trade-off in collateralization ratio setting is a direct tension between 'safety buffer' and 'capital efficiency.'
High collateralization ratio (200%+): low liquidation risk, low psychological pressure, suitable for users who don't frequently monitor positions. The cost is low capital utilization — the same collateral can borrow fewer stablecoins, and if your goal is leverage through lending, a high ratio directly limits your profit potential.
Low collateralization ratio (115-130%, near liquidation line): high capital efficiency, more stablecoins borrowable from the same collateral, maximum leverage effect. But requires near-real-time market monitoring — any rapid decline can trigger liquidation before you can react. Suitable for advanced users who can monitor 24/7 with deep market knowledge.
Recommendation for most users: choose a middle-range ratio of 160-200%, providing sufficient safety buffer without excessively wasting capital. In high-volatility market environments, proactively raising your collateralization ratio is the most direct risk-reduction action.