# USD0 Alpha (USD0a)

**USD0a** is the enhanced‑yield mode of **USD0**: a market‑neutral, value‑accruing USD savings instrument built on Usual Protocol’s stablecoin infrastructure.

USD0a is constructed on a **CME‑listed dated futures basis strategy** (**long spot, short dated futures**). It does **not** rely on perpetual futures funding rates and does **not** take directional crypto exposure. Instead, yield is driven primarily by the **structural convergence of dated futures prices toward spot at maturity** (i.e., “basis” carry), which is generally more predictable than volatile perp funding.

Users mint USD0a using **USD0 or USDC**. USD0a is **non‑rebasing**: its value accrues through an increasing on‑chain `exchangeRate`. Over time, **1 USD0a redeems for more USD0**, enabling redemption back into **USDC** at higher amounts as the underlying NAV grows.

USD0a is **fully on‑chain**, **permissionless**, and designed to be transparent and composable as a USD savings primitive.

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## Key Facts

* **Collateral composition**
  * **90% USCC** — a regulated basis‑carry fund (long spot BTC/ETH, short **CME dated futures**)
  * **10% USTB + USDC** — U.S. Treasury Bills (via Superstate) and cash‑equivalents, serving as a liquidity buffer
* **Design**: **Non‑rebasing**, **exchange‑rate accrual** (similar to how **USUALx** appreciates vs **USUAL**)
* **Access**: Fully permissionless — **no KYC/KYB**
* **Yield source**: **CME BTC/ETH basis carry** + **T‑Bill yield**
* **Value growth**: `exchangeRate(t) ≥ 1` — the exchange rate **only increases over time** as NAV grows
* **Redemption**: `1 USD0a → USD0 × exchangeRate(t)` — redeemable for USD0 at the current exchange rate
* **Redemption cycle**: Up to **7 days**, with an approximately **10% instant liquidity buffer** for smaller redemptions

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## How It Works

1. **Mint**
   * Convert **USDC or USD0** into **USD0a**.
   * Funds are allocated across:
     * **USCC** (Superstate’s basis‑carry fund), and
     * a **USTB + USDC** liquidity buffer.
2. **Receive**
   * You receive **USD0a tokens immediately**, representing a proportional claim on the underlying reserves.
3. **Accrue**
   * Yield accrues passively as the underlying **NAV increases**, which is reflected entirely through a rising on‑chain `exchangeRate`.
   * No claiming, no manual compounding: the token’s redemption value increases over time.
4. **Redeem**
   * Redeem at any time to receive **USDC plus accrued yield**.
   * **Smaller redemptions** may be fulfilled instantly from the **USDC buffer**.
   * **Larger redemptions** settle within up to **7 days**, as underlying positions unwind.

This structure provides a transparent, on‑chain, market‑neutral USD savings instrument—extending the USD0 ecosystem beyond T‑Bill yield into enhanced‑return territory.

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## Benefits

* **Predictable carry**
  * Yield is driven by **dated‑futures convergence toward spot at maturity**—a structural, well‑understood mechanism—rather than volatile perpetual funding rates.
* **Market‑neutral**
  * The **long spot / short futures** construction minimizes directional exposure to BTC and ETH price movements.
* **Value‑accruing by design**
  * All yield is reflected through the increasing `exchangeRate`, visible on‑chain.
* **Permissionless access**
  * Open minting and redemption with no access restrictions, consistent with Usual’s permissionless DeFi infrastructure.
* **Liquidity and stability buffer**
  * The **10% USTB + USDC** allocation provides a liquidity cushion backed by short‑duration U.S. Treasury Bills and cash‑equivalents—the same asset class underpinning USD0.
* **DeFi‑compatible**
  * The non‑rebasing, exchange‑rate model simplifies integration with lending markets, DEXs, and yield aggregators (no rebase accounting complexity).

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## USD0 vs. USD0a

| Feature          | USD0                                | USD0a                          |
| ---------------- | ----------------------------------- | ------------------------------ |
| **Purpose**      | Settlement asset / stablecoin       | Enhanced‑yield savings mode    |
| **Value**        | Pegged **1:1** to USD               | Grows via `exchangeRate`       |
| **Access**       | Free mint / redemption              | Mint via **USDC/USD0 vault**   |
| **Yield source** | T‑Bills / MMFs (via RWA collateral) | **CME basis carry + T‑Bills**  |
| **Design**       | Stablecoin (pegged)                 | Market‑neutral, value‑accruing |

USD0a complements the broader Usual suite:

* **USD0** is the stable, RWA‑backed settlement layer.
* **bUSD0** is the **Liquid Bond Token** (formerly **USD0++**), which locks USD0 for USUAL coupon yield.
* **USD0a** provides a third path: **enhanced USD‑denominated yield** via a market‑neutral basis strategy—without token locking, exposure to USUAL emissions, or reliance on funding‑rate markets.

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## Relationship to the Usual Ecosystem

USD0a sits within Usual’s **Product Offerings Layer**, alongside **bUSD0** (Liquid Bond Token), **sUSD0** (Savings USD0), and the **USUAL/USUALx** governance and staking stack.

* **bUSD0** generates yield through **daily USUAL token coupons** tied to T‑Bill revenue.
* **sUSD0** provides a wrapped yield‑bearing USD0 position.
* **USD0a** generates yield from an independent source: the **CME dated futures basis trade**, diversifying protocol yield beyond core RWA collateral.

As a **non‑rebasing, exchange‑rate‑accrual** token, USD0a follows the same design pattern as **USUALx** (where the USUALx:USUAL exchange rate appreciates as staking rewards accrue). This makes USD0a immediately familiar to existing Usual users and straightforward to integrate across DeFi.

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## Risks

* **Liquidity / forced unwind risk**: large redemptions can force early unwind/roll of the carry trade, crystallizing losses or giving up expected carry.
* **Basis dislocation risk**: even if Δ-neutral, the basis can gap/widen in stress potentially leading to mark-to-market drawdowns and worse exits (could create impermanent losses which resorb by itself at maturity,).
* **Redemption timing risk**: redeem anytime but can take up to \~7 days; only \~10% is intended as an instant buffer,  exits may be delayed under stress.
* **Counterparty / execution-chain risk**: reliance on USCC + TradFi custody/clearing/settlement/ops introduces operational and counterparty failure modes.
* **On-chain wrapper risk**: smart-contract bugs plus admin/upgrade/parameter changes affecting exchange-rate accounting or redemption paths.