❓FAQs

Frequently asked questions about the Fixed-Rate Lending Protocol

Platform basics

What is Secured Finance?

A DeFi platform for fixed-rate, fixed-term lending and borrowing, built on a fully on-chain order book and Zero-Coupon bonds, live on Ethereum, Arbitrum, and Filecoin. Secured Finance also operates the USDFC stablecoin on Filecoin.

What is a Zero-Coupon (ZC) bond?

A debt instrument sold at a discount and worth its full face value (100) at maturity. Buy at 95, hold to maturity, receive 100 — the 5-point discount is your fixed interest. Details: Zero-Coupon Bonds.

What asset underlies each ZC bond?

The specific currency of that market: lending ETH in the DEC2026 market gives you a claim denominated in ETH (ZC ETH DEC2026). Each bond is asset-specific, maturity-specific, and can be tokenized as an ERC-20 for use across DeFi.

Trading

Is my money locked until maturity?

No — there is no lock-up. Positions can be unwound (closed at the current market price) 24/7, subject to order-book liquidity. Lending positions can also be tokenized and transferred. Note the flip side: exiting requires an action — the protocol never auto-settles at maturity. See Managing Your Positions.

What happens to my position at maturity?

It auto-rolls into the nearest 3-month market at a fair roll price. Auto-Roll is protocol-wide — there are no settings to enable or disable. To receive your funds instead, unwind manually before or after maturity. See Fixed Maturity & Auto-Roll.

What happens to my open orders at maturity?

Unfilled orders expire automatically and the allocated funds return to your deposit balance, ready to withdraw or reuse. Filled portions become positions and follow the Auto-Roll rules above.

Why is my unwind order "Blocked" or "Partially Blocked"?

Either the order book lacks matching liquidity, or execution would fall outside the Circuit Breaker's allowed price range for this block. Wait for liquidity and retry, or place an opposite limit order at your acceptable price — filled amounts net against your position. See Order Life Cycle.

What fees do I pay?

The taker side of a fill pays the trading fee (1% p.a. prorated — 0.25% for 3 months): market orders, and the portion of a limit order that crosses the book and fills immediately. Volume resting on the book pays nothing. Auto-Rolls charge the same rate as the taker fee each quarter. Liquidated borrowers pay a 7% liquidation fee. Full details: Fees and Protocol Parameters.

Collateral & risk

Why do borrowers need collateral?

Collateral replaces credit checks: it protects lenders from default because under-collateralized positions are liquidated before losses reach lenders. See Collateral.

Which assets can be collateral?

It varies by network — WBTC, ETH, USDC, and uMINT (RWA) on Ethereum; WBTC, ETH, and USDC on Arbitrum; FIL, iFIL, wpFIL, and USDFC on Filecoin. The authoritative list, with haircuts: Protocol Parameters.

What happens if my collateral value falls?

Your LTV rises. At the liquidation threshold (80%), up to 50% of your debt can be liquidated with a 7% fee taken from collateral. Watch the risk indicator in Portfolio and add collateral or reduce debt early. See Liquidation.

Advanced

What is Itayose?

The opening auction that sets a fair price whenever a new quarterly market launches: pre-open orders are collected for 7 days and matched simultaneously at the volume-maximizing price — with zero fees for filled pre-orders. See Itayose.

How can the order book be fully on-chain? Isn't that too expensive?

It's economical thanks to three techniques: Red-Black Trees for O(log n) order management, lazy evaluation to defer storage writes, and Genesis Value accounting to roll all positions with one update. See the Orderbook Deep Dive.

Can I run a liquidation bot?

Yes — liquidation is permissionless and pays a 5% fee to the liquidator. Start with the Liquidator's Guide.

Still stuck?

• Guides: Getting Started

• Developers: Developer Portal

• Community support: Support & Contacts