> For the complete documentation index, see [llms.txt](https://docs.secured.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.secured.finance/fixed-rate-lending/advanced-topics/orderbook-deep-dive/orderbook-rotation.md). # Orderbook Rotation At the full standard configuration, each currency runs **9 order books (8 active + 1 inactive) inside a single lending market contract**; a market with less liquidity may keep fewer maturities open. Rather than creating new order books each quarter, matured ones are **recycled** — a design that both avoids deployment costs and caps the data volume that [lazy evaluation](/fixed-rate-lending/advanced-topics/orderbook-deep-dive/lazy-evaluation.md) must handle. ## The cycle 1. The **inactive** order book opens a **7-day pre-order period** for the next new maturity (2 years out), ending 1 hour before the nearest active book matures. 2. At maturity: the [Itayose](/fixed-rate-lending/advanced-topics/itayose.md) auction runs and the new book **activates**; the matured book's positions [auto-roll](/fixed-rate-lending/core-concepts/fixed-maturity-and-auto-roll.md); the matured book itself moves to the end of the queue and becomes the new **inactive** book. 3. The cycle repeats every quarter. **Example (ETH):** active books MAR2026…DEC2027, inactive book preparing MAR2028. When MAR2026 matures, MAR2028 opens via Itayose, MAR2026's positions roll into JUN2026 (nearest 3-month), and the MAR2026 order book is recycled to prepare JUN2028.

Market Life Cycle

## Why exactly 9? * **Gas bound** — order placement and matching never consider more than 8 active books' data; lazy evaluation has a fixed-size working set. * **Liquidity concentration** — 8 quarterly points cover 2 years without fragmenting volume across dozens of dates. * **No deployment churn** — recycling reuses order books within the same contract, so the protocol's address surface stays stable. ## Related * [Fixed Maturity & Auto-Roll](/fixed-rate-lending/core-concepts/fixed-maturity-and-auto-roll.md) — the user-facing view of the same cycle * [Itayose](/fixed-rate-lending/advanced-topics/itayose.md) — how the new book's opening price is set