# Markets - Curve AMM

Napier also supports markets built on **Curve’s Two-Crypto-NG AMM**, in addition to the native Napier AMM.

The general design of **Markets, Permissionless Creation, Fees, Roles, Market Categories, and Core Interactions** remains as described in the previous section ([Markets - Napier AMM](https://docs.napier.finance/learn/protocols/markets-napier-amm)). This page focuses on features unique to Curve AMM–based markets.

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### Core Concepts

* [**Curve Two-Crypto-NG Pool**](https://github.com/curvefi/twocrypto-ng)

  Instead of Napier’s time-adaptive AMM curve, these pools use Curve’s Two-Crypto-NG invariant. Pools are structured as PT/underlying pairs (e.g., PT-sUSDe / sUSDe). Two-Crypto-NG is designed for pairs that are highly correlated but not perfectly stable, making it well-suited to PT/underlying markets where PT converges to the underlying at maturity.
* **Execution System**

  As with Napier AMM, the unified router atomically handles issuance, redemption, swaps, and liquidity actions in a single transaction.

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### Key Features

* **Adaptive Invariant**

  Two-Crypto-NG generalizes Curve’s invariant to handle correlated assets with some volatility. This allows efficient swaps even when PT diverges modestly from the underlying, while still converging smoothly toward parity at maturity.
* **Simplified Liquidity Provision**

  Unlike Napier AMM’s yield-band concentration, liquidity in Two-Crypto-NG pools spans the entire range. LPs do not need to configure APY bands, which lowers operational complexity.
* **Ecosystem Integration**

  Pools deployed on Curve AMM can integrate directly with Curve’s existing ecosystem—gauges, rewards, and veCRV incentives—enabling curators to bootstrap liquidity beyond Napier’s native mechanisms.

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### Differences from Napier AMM

| Aspect                  | Napier AMM (Custom v4 Hook)                                                                                                                                    | Curve AMM (Two-Crypto-NG)                                                                                                                                                                                                              |
| ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Trading curve design    | Time-adaptive curve converging toward flatness at maturity                                                                                                     | Two-Crypto-NG invariant for correlated but volatile pairs                                                                                                                                                                              |
| Swap Fee                | <p></p><ul><li>Flat percentage swap fee (not maturity-dependent)</li><li>Fees distributed between  <strong>LPs and the Curve DAO (50%: 50%)</strong></li></ul> | <p></p><ul><li>Percentage fee on the <em>yield-receivable</em> portion of PT (higher for longer maturities, lower for shorter)</li><li>Fees distributed between <strong>LPs and Napier Curators (Curator-set ratio)</strong></li></ul> |
| IL mitigation           | PT appreciation + band concentration                                                                                                                           | Efficient handling of correlated assets without explicit banding                                                                                                                                                                       |
| LP strategy             | Select implied-APY bands for higher efficiency                                                                                                                 | Provide liquidity across the full curve, simpler UX                                                                                                                                                                                    |
| Ecosystem integration   | Native to Uniswap v4 Hook–based                                                                                                                                | Curve-native incentives (gauges, veCRV)                                                                                                                                                                                                |
| Rehypothecation support | Supported                                                                                                                                                      | Not supported                                                                                                                                                                                                                          |

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### Incentives

* **For LPs**: Earn fees from PT/underlying trades without needing to actively manage liquidity ranges; potential to stack Curve gauge rewards.
* **For Curators**: Configure markets that tap into Curve’s veCRV incentive system, aligning Napier’s yield trading with Curve’s liquidity engine.
* **For Traders**: Benefit from deep liquidity and efficient execution even when PT deviates moderately from the underlying, with convergence ensured as maturity approaches.

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### Example

A PT-sUSDe / sUSDe market deployed on Curve AMM uses the Two-Crypto-NG invariant.

* LPs deposit liquidity once, without choosing yield bands, and earn both trading fees and potential Curve incentives.
* Traders execute PT ↔ sUSDe swaps with low slippage, even if yields shift before maturity.
* Curators may direct veCRV incentives toward their market, attracting deeper liquidity from Curve’s ecosystem.

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### Get Involved

Napier Markets are open and composable by design. Choose your path and dive deeper with the dedicated guides:

* **For Users** → User Guide: Learn how to trade PT/YT, provide liquidity, and use PT as collateral.
* **For Curators** → Curator Guide: Understand how to launch markets, configure parameters, and build your own onchain yield products.
* **For Builders** → Developer Guide: Integrate Napier Markets into your protocol with SDKs and APIs.