LTV (Loan-to-Value) is not unique to DeFi — traditional mortgages use it too. Buy a $1M home, put down $200K, borrow $800K from a bank: that loan's LTV is 80% (800 ÷ 1,000). In DeFi lending, the logic is identical — only the collateral changes from a property to crypto assets or RWA tokens, and calculation is real-time. Concrete example: deposit $10,000 OUSG into Flux Finance. Flux allows a maximum LTV of 92% on OUSG, meaning you can borrow up to $9,200 USDC. But borrowing at the ceiling leaves your position extremely fragile — any minor negative fluctuation in OUSG's NAV (or rising borrow rates increasing your effective loan amount) can trigger liquidation. In practice, most experienced borrowers keep active LTV at 70-75% of the protocol ceiling, maintaining enough buffer.
Different assets have different maximum LTV limits because they have different volatility profiles. When DeFi protocols set LTV ceilings, they're essentially stating: 'How much could this asset drop in extreme conditions, and how much buffer do I need before the borrower is liquidated?' Higher volatility assets get lower LTV ceilings. Using Aave as example: USDC (stablecoin, near-zero volatility): max LTV ~90%. ETH (major crypto, moderate volatility): max LTV ~80%. WBTC (wrapped Bitcoin, similar volatility to ETH): max LTV ~73%. PAXG (tokenized gold, lower volatility than ETH): max LTV ~67%. OUSG (tokenized Treasuries, NAV barely fluctuates and rises slightly each day): max LTV ~92% (on Flux Finance). OUSG's high LTV ceiling is possible precisely because its underlying is US government debt — essentially zero chance of a major price collapse. This is RWA tokens' natural advantage as DeFi collateral.
Health Factor (HF) is the real-time safety score for your LTV position in a specific protocol — a more intuitive monitoring metric than raw LTV. Health Factor = (Collateral Value × Liquidation Threshold) ÷ Loan Amount. When HF > 1.0, your position is safe. When HF = 1.0, you're exactly at the liquidation boundary. When HF < 1.0, liquidation is triggered. Practical target ranges: HF > 2.0: very safe but low capital efficiency (you're under-borrowing). HF 1.5-2.0: reasonable safety margin, appropriate for most scenarios. HF 1.3-1.5: close monitoring needed; set alerts. HF < 1.3: danger zone; consider adding collateral or repaying to lower LTV. HF < 1.0: liquidation triggered or imminent. For OUSG-collateral borrowers, Health Factor naturally rises slightly each day as OUSG's NAV increases — a natural buffer no other collateral type provides.
LTV management has several practical strategies suited to different risk preferences. Conservative: fix LTV at 50-60%, minimal active management needed, only monitor during extreme market volatility. Suitable for users seeking long-term stable capital efficiency improvements without active management time commitment. Moderate: dynamically manage LTV at 65-75%, maintaining higher capital efficiency in stable markets, proactively reducing LTV when market stress signals appear (rising borrow rates, increasing asset price volatility). Aggressive: push LTV to 80-85%, maximizing capital efficiency, but requiring automated liquidation defense mechanisms (some protocols offer auto-collateral-top-up features) and close monitoring. Special note for RWA tokens (especially OUSG): since OUSG's NAV rises daily, your effective LTV naturally decreases each day. This means you can set a slightly higher initial LTV and rely on NAV's natural growth to maintain safety margin — an advantage completely unavailable with pure crypto collateral.
A holder of $50,000 PAXG (tokenized gold) wants liquidity without selling his gold. He deposits PAXG in Aave; Aave's max PAXG LTV is 67%, allowing up to $33,500 borrowing. He decides to be conservative, borrowing only $25,000 USDC (effective LTV = 50%) and setting a Health Factor alert below 1.5. He calculates: even if gold prices fall 30% in the short term (PAXG drops to $35,000), his HF would be approximately ($35,000 × 67%) ÷ $25,000 = 0.938 — below 1.0. This reveals that his 50% LTV would actually still be unsafe in a 30% gold drop. Recalculating, he reduces his borrow to $15,000 (effective LTV = 30%), so even if gold drops 30%, his HF is ($35,000 × 67%) ÷ $15,000 = 1.56 — in the safe range. This calculation process illustrates the core LTV-setting logic: ask not 'is this safe in normal conditions?' but 'how much buffer remains in extreme conditions?'
LTV is fundamentally a trade-off between capital efficiency and liquidation risk: higher LTV means more borrowing power per unit of collateral and higher capital efficiency, but greater liquidation risk. Lower LTV means more safety, but lower capital efficiency — effectively 'idling' part of your collateral. Special advantage of RWA tokens (especially tokenized Treasuries) as collateral: OUSG's NAV rises daily, meaning your collateral automatically appreciates. Effective LTV naturally falls each day, providing continuous safety buffer. This gives RWA tokens more stable risk characteristics as lending collateral compared to crypto assets — you don't need to intervene as frequently as with ETH collateral. Just set the initial LTV more conservatively, then monitor at lower frequency.