> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hylo.so/llms.txt
> Use this file to discover all available pages before exploring further.

# Earn Pool

> Earn Pool hyUSD and its yield sources.

**hyUSD** holders can earn yield by depositing into Hylo's Earn Pool. The pool aggregates yield from all collateral pools and distributes it to depositors automatically.

## Earn Pool hyUSD

Earn Pool **hyUSD** (**eHYUSD**) is a tokenized, yield-bearing version of **hyUSD** that represents a user's deposit in the Earn Pool.

When users deposit **hyUSD**, they receive **eHYUSD** tokens representing their pro rata share of the pool. **eHYUSD** compounds yield at the end of each network epoch.

<Note>
  **eHYUSD** is the same token as **sHYUSD**: same mint address, only the ticker has changed for Hylo V2. No migration or action of any kind is needed from holders.
</Note>

## Yield Sources

Yield is aggregated from the protocol's underlying collateral pools:

<CardGroup cols={2}>
  <Card title="SOL Pool Yield" icon="coins">
    Native staking rewards from LSTs
  </Card>

  <Card title="BTC Pool Yield" icon="bitcoin">
    Borrow rate charged to **xBTC** holders
  </Card>
</CardGroup>

### Total Protocol Yield

The combined yield from all collateral pools flows to the Earn Pool:

$$
\text{Total Yield} = \sum_{i \in C}(\text{Pool}_i \text{ TVL} \cdot \text{Pool}_i \text{ Yield Rate})
$$

## Earn Pool APY

**eHYUSD** holders collect rewards from the entirety of Hylo's TVL across all pools.

<Frame>
  <img src="https://mintcdn.com/hylo/VbP8KOSnAwWe_lMh/images/ehyusd-yield-sources.png?fit=max&auto=format&n=VbP8KOSnAwWe_lMh&q=85&s=c3f5c5883e855404c14c0842e6924e3e" alt="eHYUSD receives yield from all xAsset pools" width="2880" height="1354" data-path="images/ehyusd-yield-sources.png" />
</Frame>

<Note>
  [USTB](https://superstate.com/assets/ustb) yield on USDC will be added in the coming weeks, adding a base yield of **3.78% APY**.
</Note>

### APY Calculation

The per-epoch rate is:

$$
\text{Epoch Rate} = \frac{\text{Epoch Yield} \cdot \text{Pool Allocation}}{\text{hyUSD in Earn Pool}}
$$

The **pool allocation** is a configurable protocol parameter that determines how much of the harvested yield flows to the Earn Pool versus the treasury. The APY is then annualized across Solana's 182.5 epochs per year:

$$
\text{Earn Pool APY} = (1 + \text{Epoch Rate})^{182.5} - 1
$$

<Accordion title="Example: Multi-Pool Yield Boost">
  This example demonstrates how the Earn Pool offers higher yields by aggregating returns from multiple collateral pools.

  **Hypothetical Setup:**

  * **SOL Pool:** 80M TVL, 6% staking yield
  * **BTC Pool:** 20M TVL, 5% borrow rate
  * **hyUSD Supply:** 70M
  * **hyUSD in Earn Pool:** 70% (49M)

  **Revenue Generation:**

  * SOL Pool: 80M × 6% = 4.8M/year
  * BTC Pool: 20M × 5% = 1.0M/year
  * **Total:** 5.8M/year

  **Effective Yield (assuming all yield flows to Earn Pool depositors):**

  $$
  \text{Effective Yield} = \frac{5.8M}{49M} \approx \textbf{11.8\%}
  $$

  Because only **hyUSD** in the Earn Pool earns yield, the effective APY is amplified beyond any individual pool's rate.
</Accordion>

## How Yield Compounds

Every epoch, yield generated by all collateral pools is "harvested" via a permissionless crank:

1. **SOL Pool:** LST yield accrues automatically as LST prices appreciate
2. **BTC Pool:** Borrow rate is collected from the pool's collateral
3. **Distribution:** Yield is converted into newly minted **hyUSD**
4. **Compounding:** **hyUSD** added to the Earn Pool increases **eHYUSD** NAV

This mechanism causes **eHYUSD** to continuously appreciate against **hyUSD**.