I already have ETH — why borrow DAI instead of just selling ETH? What's the practical benefit?
This is the most direct motivation for using crypto-backed stablecoins. Three common reasons to borrow DAI rather than sell ETH:
First, retain long-term ETH price exposure: if you believe ETH will appreciate long-term, selling means giving up future upside. Borrowing DAI lets you access stablecoins for other purposes (paying fees, DeFi operations) without selling ETH — repaying later lets you reclaim ETH and enjoy appreciation.
Second, avoid or defer capital gains tax: under some tax frameworks, selling crypto assets creates taxable events; borrowing does not. Using DAI instead of selling can provide liquidity without triggering tax events (general situation — consult a local tax advisor for specific advice).
Third, DeFi strategy leverage tool: borrow DAI then use it to buy more ETH (looping operation) — effectively leveraged ETH long, with higher capital efficiency than traditional financing.
Cost to note: Stability Fee must be paid during the borrowing period (approximately 5-8% annualized); if ETH drops sharply and collateral ratio falls below Liquidation line, ETH gets force-sold — which is actually the worst-case passive sell outcome. Borrowing DAI therefore requires you to tolerate short-term collateral volatility and have the ability to add collateral when necessary.
What is the biggest risk of crypto-backed stablecoins? What do beginners especially need to watch out for?
The biggest risk is Liquidation — and liquidation is immediate and irreversible. For beginners, these points particularly need attention:
The real cost of the liquidation mechanism: it's not just losing collateral — liquidation also charges a penalty (typically 13%). If you deposited $1,500 ETH to borrow $1,000 DAI, when liquidation triggers, the system auctions your ETH at a discount. After deducting the $1,000 DAI debt and 13% penalty, you might recover only around $170 — not the theoretical $500 buffer.
Market volatility moves faster than reaction time: a 20% crypto market drop within hours is common. If your collateral ratio is 130%, ETH dropping 17% could trigger liquidation. If you're asleep or offline, liquidation has already happened.
Gas fees spike in extreme markets: the 2020 Black Thursday case shows that when you most need to add collateral, Ethereum network congestion is typically at its worst — gas fees can make adding collateral far more expensive, or even too costly to execute in time.
Advice for beginners: for your first MakerDAO operation, aim for at least 200% collateral ratio (deposit $2,000 ETH to borrow only $1,000 DAI), and set up DeFi tracking tools (DeBank, etc.) with collateral ratio alerts to give yourself adequate reaction time.
What are the respective advantages of DAI and USDC in DeFi? When should you choose which?
Their advantages are complementary — choice depends on your purpose:
Choose DAI when: needing censorship resistance — Circle can freeze specific USDC addresses; MakerDAO's DAI contract has no equivalent blacklist; operating in protocols that accept DAI but not USDC; valuing decentralization principles and willing to bear overcollateralization capital efficiency losses; using sDAI for DSR yield (currently approximately 5-6% annualized — similar to permissionless on-chain Treasury yield).
Choose USDC when: needing the broadest platform and protocol support; institutional or corporate payment scenarios (higher compliance transparency); operating in the Coinbase ecosystem (zero-fee conversion); frequent operations needing simple management (no need to maintain Vault collateral ratios).
Curve 3pool is a scenario for using both: providing liquidity simultaneously in DAI, USDC, and USDT in Curve's 3pool captures trading fees from all three stablecoins, with their characteristics complementing each other — DAI's decentralization, USDC's compliance, USDT's liquidity.
Why is the scale of crypto-backed stablecoins far smaller than fiat-backed? Will this landscape change?
The structural capital efficiency limitation is the most fundamental reason — unlikely to change dramatically in the short term.
Reasons for the market size difference: DAI and similar crypto-backed stablecoins have circulation of approximately $5-8 billion, while USDC is $76B and USDT $115B. The root cause is the overcollateralization mechanism's limitation — issuing $1 of DAI requires $1.5+ in crypto assets locked. This means crypto-backed Stablecoin scale expansion directly depends on the number of users willing to lock large amounts of crypto as collateral — a demand inherently far smaller than 'simply holding USDC.'
Why fiat-backed scales more easily: Circle issuing one USDC only requires the corresponding $1 entering the system; MakerDAO issuing one DAI requires users to actively deposit $1.50 in collateral and bear Liquidation risk. One is passive holding, the other is active management — natural demand scale differences.
Future direction for potential change: if RWA tokenized Treasuries continue expanding as a proportion of collateral (DAI already has over 50% of reserves as RWA), the boundary between crypto-backed and fiat-backed will increasingly blur. But purely crypto-asset overcollateralized scale is expected to remain at approximately 5-10% of the total stablecoin market long-term.
Using a simple scenario to illustrate the complete borrow-and-repay flow of crypto-backed stablecoins.
Scenario: Xiao Chen holds 2 ETH, wants $1,000 for DeFi but doesn't want to sell ETH
Xiao Chen holds 2 ETH at $1,500 each (total value $3,000). He believes ETH will appreciate and doesn't want to sell. But he needs $1,000 to participate in a DeFi liquidity mining opportunity.
Steps: First, Xiao Chen goes to Sky Protocol (sky.money), opens a Vault, and deposits 2 ETH as collateral. Second, the system confirms collateral ratio 3,000 ÷ 1,000 = 300%, well above the liquidation line, and approves borrowing 1,000 DAI. Third, Xiao Chen uses 1,000 DAI for DeFi liquidity mining, earning approximately 5% annualized while paying the Vault's Stability Fee at approximately 6% (rate differential -1%, but he's betting ETH appreciation covers the cost). Fourth, three months later, ETH rises to $1,800 (total value $3,600) — he unwinds the DeFi position, repays the Vault with 1,000 DAI + 15 DAI in stability fees (3 months × 6% ÷ 12 × 1,000), and reclaims 2 ETH.
Outcome: Xiao Chen's 2 ETH is now worth $3,600 (vs original $3,000, +$600), plus earnings from DeFi liquidity mining — paying only 15 DAI in borrowing interest. Had he sold ETH originally, he would have missed $600 in appreciation.
The core trade-off of crypto-backed stablecoins is an exchange between 'full decentralization and censorship resistance' and 'low capital efficiency and active management requirements.'
What you get: no institution can freeze your DAI (unlike Circle freezing USDC); the entire system is transparent and verifiable without trusting any company; access to stablecoin liquidity without selling crypto assets; on-chain yield through sDAI.
What you give up: requires overcollateralization (150%+ capital lock-up efficiency loss); need to actively monitor collateral ratio or face liquidation; pay Stability Fee (borrowing interest); learning curve to understand and operate Vaults; 13% penalty risk at liquidation.
Who is best suited for crypto-backed stablecoins: intermediate-to-advanced DeFi users with significant ETH/BTC who want liquidity without selling; users who value censorship resistance and have the ability to actively manage positions. For everyday payments or simple stablecoin holding, fiat-backed remains the more practical choice.
Missing Link: Most people only think of liquidation as the risk — but they miss the deeper design paradox: the safer you play it (high collateral ratio), the more capital you lock up doing nothing, yet you contribute the most buffer to the system. The users operating close to the 130% edge are actually using the mechanism as intended — they're just absorbing nearly all the liquidation risk on everyone else's behalf.