Crypto lending explained how it works and key risks in 2025

Crypto lending platforms collectively locked over $20 billion in assets by early 2026, marking the sector as one of DeFi’s largest segments and a growing source of liquidity for long‑term holders【1】. The rapid expansion brings heightened attention to over‑collateralized loans, flash‑loan arbitrage, and the heightened liquidation and smart‑contract risks that have already caused multi‑hundred‑million‑dollar losses.

How crypto lending works

Both decentralized finance (DeFi) protocols and centralized exchanges let users either borrow digital assets against collateral or earn interest by depositing crypto into pooled lending contracts. On DeFi platforms, smart contracts automatically enforce over‑collateralization—commonly requiring borrowers to lock assets worth twice the loan amount (e.g., $200 of ETH to borrow $100 stablecoins)【1】. If collateral value falls below a predefined threshold, the contract liquidates the position to protect lenders. Centralized platforms perform the same function manually, acting as the intermediary that manages collateral requirements and distributes interest.

Key loan types and risks

Collateralized loans dominate the market, with a typical LTV of 50 % that dictates how much credit a borrower can draw against their crypto holdings【2】. Borrowers must monitor their LTV; a price drop in the underlying asset raises the ratio and can trigger liquidation warnings. Flash loans require no collateral but must be repaid within a single blockchain transaction; they enable arbitrage but have also been exploited in attacks, exemplified by a $290 million loss on a major DeFi platform in April 2026【1】. Additional risks include smart‑contract vulnerabilities, platform insolvency (e.g., Celsius and BlockFi collapses in 2022), custody exposure, and evolving regulatory scrutiny in the U.S. and EU【1】.

Leading protocols

Aave, the largest DeFi lender by TVL, introduced its V3.2 upgrade in May 2024, adding multi‑chain support and tighter risk isolation【1】. Compound remains a core protocol despite being eclipsed by Aave in recent TVL rankings. Both rely on tokenized receipt assets (aTokens for Aave) that accrue interest automatically for lenders.

What to watch

• Collateral health thresholds – monitor price levels that would push typical 50 % LTV positions into liquidation zones (e.g., ETH price drops of 30 % or more).
• Flash‑loan activity spikes – on‑chain metrics showing unusually high flash‑loan volumes may precede arbitrage opportunities or potential exploit attempts.
• Regulatory updates – upcoming U.S. and EU guidance on crypto lending services could affect platform compliance and user access.

The rise of crypto lending underscores a shift from pure holding to active asset management, but the sector’s growth is tightly coupled with systemic risks that could reshape liquidity provision if major incidents recur.