What is the fundamental difference between a CDP and direct borrowing (like a credit loan)? Why is 'overcollateralization' required?
The fundamental difference is the trust mechanism. Traditional credit loans rely on 'credit assessment of the borrower' — the bank believes you can repay, so they're willing to lend. CDPs have no credit review; anyone can use them, so they must rely on 'forced collateral liquidation mechanisms' to ensure system safety.
Why overcollateralize: Crypto assets like ETH are highly volatile. If you could borrow 1,000 DAI against 1,000 dollars of ETH (100% collateral ratio), ETH dropping just 1% would make collateral worth less than debt — the system immediately becomes insolvent. Overcollateralization (e.g., 150%) gives collateral sufficient buffer — ETH would need to drop over 33% to trigger liquidation, giving markets and users time to respond.
The cost: you lock up $1,500 of ETH to borrow $1,000 DAI. That extra $500 in collateral is the capital efficiency cost you pay to use the system.
What is the complete process of opening a CDP? Can ordinary people operate it themselves?
Complete process (using MakerDAO as example):
Step 1: prepare an Ethereum wallet (like MetaMask) and ETH.
Step 2: go to oasis.app or app.sparklend.com, connect wallet.
Step 3: select 'Borrow' or 'Open Vault', choose collateral type (ETH-A, WBTC, etc.).
Step 4: enter the amount of ETH to deposit; the system shows the maximum DAI you can borrow and the corresponding collateral ratio. Recommended to maintain ratio above 200%.
Step 5: confirm transaction, pay Gas fee; DAI will appear in your wallet.
Step 6 (repayment): when you want to retrieve your ETH, prepare the equivalent DAI + accumulated Stability Fee, click 'Repay' in the interface.
Can ordinary people operate it: technically yes, but requires basic DeFi knowledge (wallet management, Gas fees, liquidation risk). If you've never used DeFi, practice with a small amount first, and you need to closely monitor ETH prices throughout — if you're not comfortable actively managing risk, the cost of using a CDP may exceed the benefits.
What happens during a CDP 'liquidation'? Will I lose all my collateral?
Liquidation doesn't mean 'losing everything' — but there will be significant losses. Here's the complete liquidation process:
Trigger: your collateral ratio (collateral market value ÷ borrowed DAI) falls below the system's liquidation threshold (ETH-A is 150%).
Liquidation execution: Keeper bots (automated on-chain arbitrage bots) detect your CDP has entered liquidation and immediately begin auctioning your collateral at a slight discount from market price.
Fund allocation: auction proceeds → first repay your DAI debt → deduct liquidation penalty (ETH-A is 13%) → remaining assets returned to you.
Example: you have 2 ETH (market value $3,000), borrowed 1,500 DAI (200% collateral ratio). ETH drops to $1,125 each, value falls to $2,250, collateral ratio = 150%, triggering liquidation. System auctions your ETH, recovers 1,500 DAI debt + 195 DAI (13% penalty); remaining ETH equivalent of ~$555 is returned to you. Loss: you lose $195 in penalty + liquidation discount — but not 'zeroed out.'
Key lesson: liquidation is avoidable — as long as you proactively add collateral or repay some DAI before the ratio approaches danger levels.
Compared to other borrowing methods (like crypto collateral lending platforms), what are CDP's advantages and disadvantages?
Vs. centralized lending platforms (Nexo, Ledn, etc.):
Centralized platform advantages: simpler operation (similar to traditional finance), customer service support, no DeFi knowledge needed. Disadvantages: counterparty risk (FTX users learned this the hard way), requires KYC, assets handed to third-party custody.
CDP advantages: decentralized, assets never leave your control (just locked in on-chain contracts), no KYC, available 24/7. Disadvantages: requires technical knowledge, liquidation risk entirely your responsibility, can't 'call to negotiate' payment extensions.
Vs. Flash Loans: flash loans are borrowed-and-repaid within the same transaction, require no collateral, but can only be used within one block (mainly for arbitrage). CDPs are 'cross-time leverage tools' allowing you to hold borrowed funds over time. Completely different use cases.
Best scenarios for CDPs: you're long-term bullish on ETH, don't want to sell, but need short-term liquidity; you have sufficient DeFi experience to actively manage liquidation risk; you value self-custody and don't want to hand ETH to a third-party platform.
Simplest CDP Usage Scenario
Wang Xiaoming has 2 ETH (currently $2,000 each = $4,000 total), needs $1,000 for an expense, but doesn't want to sell ETH (he thinks ETH will rise).
He opens an ETH-A CDP, deposits 2 ETH, borrows 1,000 DAI (400% collateral ratio — far above the 150% liquidation line). He pays the expense with 1,000 DAI. Three months later, he earns some money, repays 1,000 DAI + approximately 12.5 DAI in Stability Fees (5% annualized, 3 months) to the CDP, retrieves 2 ETH.
Result: he kept his ETH, gained liquidity, total cost only 12.5 DAI (~$12.50) in interest. If ETH rose from $2,000 to $3,000 during those three months, he earned an extra $2,000 in appreciation (much better than selling ETH directly).
If things go badly: if ETH drops to $750 each, collateral ratio falls to 150%, CDP gets liquidated. He loses 13% liquidation penalty — but not 'everything.'
CDP Core Trade-offs
✅ Retains asset appreciation potential + gains liquidity simultaneously; capital efficiency higher than selling outright
❌ Must overcollateralize (capital efficiency still lower than traditional lending); requires active liquidation risk monitoring; if ETH crashes during borrowing period, final loss may exceed not borrowing at all
Summary: CDP is 'a borrowing tool for people who believe their collateral will appreciate' — if you don't have confidence in the collateral rising, selling directly is lower risk than opening a CDP.