# Spield — Yield stripping finance on Stellar network

Spield is a yield-stripping protocol on Stellar. It turns **one yield-bearing token** into two tradable positions:

* **Principal Token (PT)**: fixed outcome at maturity.
* **Yield Token (YT)**: variable outcome, linked to realized yield.

Spield does not remove yield risk. It **routes yield risk** to the users who want it.

### What you can do

* Lock predictable value via PT (bond-like exposure).
* Speculate on yield via YT (leveraged exposure).
* Trade PT and YT independently before maturity.

### Doc set

Read in this order:

1. [Product overview](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/product-overview)
2. [Yield stripping model (PT + YT)](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/yield-stripping-model-pt-+-yt)
3. [User flows](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/user-flows)
4. [Yield index and yield calculation (YT)](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/yield-index-and-yield-calculation-yt)
5. [Maturity, settlement, and capital conservation](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/maturity-settlement-and-capital-conservation)
6. [Orderbook marketplace (PT/YT trading)](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/orderbook-marketplace-pt-yt-trading)
7. [MVP assumptions and parameters](https://spield.gitbook.io/self-docs/spield-yield-stripping-finance-on-stellar-network/mvp-assumptions-and-parameters)

{% hint style="info" %}
Key formulas used in these docs:

* **YT payout** = (currentIndex − pastIndex) × total YT bought
* **APY** = ((currentIndex / sevenDaysOldIndex)^(365/7)) − 1
  {% endhint %}