# Bucket Upgrade and Migration

This page explains the **major Bucket upgrade** and how to **migrate** from the legacy system. It is intended for:

* **Legacy CDP users**
* **BUCK holders** (including BUCK Savings positions)

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### What changed — background & purpose

The upgrade focuses on **cost efficiency, clarity, and safety**:

* **One-time borrow fee (0.3%) removed**\
  With Recovery Mode gone, a borrow fee is no longer necessary. This aligns with market practice and makes borrowing **more cost-efficient (Interest fee only)**.
* **Recovery Mode removed**\
  Reduces user learning cost and eliminates unpredictable, system-level risk interactions — you only monitor **your own CR(Collateral Ratio) / liquidation price**.
* **Tank removed (protocol-run liquidations)**\
  Liquidations are fully handled by the **protocol**. An **improved liquidation mechanism** (to further reduce user liquidation risk and potential loss) is **on the way.**
* **Position ordering removed**\
  The system no longer requires CDP ordering. This **improves scalability** and removes the **minimum debt** constraint.

Result: a simpler, safer, more cost-efficient, and more flexible CDP system.

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### Migration phases

Bucket runs migration in **phases** (progression depends on migration uptake).

* **Phase 1 — Legacy usable, migration encouraged**
  * **CDP:** Legacy positions remain fully functional. New CDPs offer **no borrow fee** and higher **Borrow Rewards**.
  * **Stablecoin Savings:** Higher **APR** on the USDB Savings Pool to encourage migration.
* **Phase 2 — Legacy exit-only**
  * **CDP:** Legacy position becomes **exit-only** (no new **Borrow**, no new positions), **BUCK minting disabled**.
  * **BUCK Savings Pool:** **Withdraw/Migrate only**.
* **Phase 3 — Legacy hidden**
  * The app UI **no longer shows** legacy CDPs / BUCK Savings positions.

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### Old positions → New positions

| Legacy                                 | New                                 | Conversion                             | Fee                   |
| -------------------------------------- | ----------------------------------- | -------------------------------------- | --------------------- |
| **BUCK**                               | **USDB**                            | **1:1 via Migrate**                    | **No fee** (gas only) |
| **Legacy CDP (BUCK-denominated debt)** | **New CDP (USDB-denominated debt)** | One-click **Migrate CDP**              | **No fee** (gas only) |
| **BUCK Savings Pool**                  | USDB **Savings Pool**               | One-click **Migrate Savings position** | **No fee** (gas only) |

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### Migrate CDP (legacy → new)

**What happens**

* Your **debt unit** changes from **BUCK** to **USDB**.
* The position moves to the **new CDP mechanism** (no borrow fee; fixed per-asset rate; protocol-run liquidation).
* **Collateral, notional debt, CR, and liquidation price** remain the same.

**Step-by-step**

1. Open **Dashboard** → find the **legacy position** → click **Migrate (Only for collateral that supported by New Market)**.<br>

   <figure><img src="https://2164669523-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fvo4y92EukVo5jeASAueL%2Fuploads%2Ff23CfMqq1JJ4mIP8TSrr%2FCleanShot%202025-09-15%20at%2000.47.00%402x.png?alt=media&#x26;token=6d2de4b5-faff-4bd1-94e3-505ee8651450" alt="" width="375"><figcaption></figcaption></figure>
2. Review the preview.<br>

   <figure><img src="https://2164669523-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fvo4y92EukVo5jeASAueL%2Fuploads%2FllTN1xfCUeAQDsyGYSoE%2FCleanShot%202025-09-15%20at%2000.47.31%402x.png?alt=media&#x26;token=2afd31a7-1548-4bcf-b86c-61dbb43ee182" alt="" width="375"><figcaption></figcaption></figure>
3. Confirm to execute (Migrate).
4. The position reappears as a **USDB-denominated CDP** under the new CDP model (New position).

**Notes**

* You **do not** need to close and reopen the vault.
* **Borrow fee = 0** on the new CDP model.

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### Migrate Stablecoin Savings

**What happens**

1. **Withdraw BUCK from BUCK Savings Pool.**
2. **Migrate BUCK → USDB (1:1)**.
3. **Deposit USDB into USDB Savings Pool.**

**Step-by-step**

1. Open **Dashboard** → find your **BUCK Savings** position → click **Migrate**.
2. Review the preview.
3. Confirm (Migrate).
4. Your new Savings position appears on New position page (USDB Savings).

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### Costs & requirements

* **Protocol migration fee:** **None** (all flows above are fee-free from the protocol).
* **Network fee:** You need some $**SUI** for gas.

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### After migration — what to expect

* **CDP:** Shown as a **New position** on your **Dashboard**, with **fixed interest rate** and **no one-time borrow fee**.
* **Stablecoin Savings:** Shown under **Stablecoin Savings** as **USDB**. Rewards are **claimable anytime** (Higher APR).