> For the complete documentation index, see [llms.txt](https://docs.btcd.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.btcd.fi/tokens.md).

# Tokens

The tokens in the Bitcoin Dollar ecosystem and how they relate.

Bitcoin Dollar uses a base token, a staking token, a governance token and vault receipt tokens.

## Core tokens

* [**BTCD**](/tokens/btcd.md) is the base token. Its peg tracks a 50/50 bitcoin/dollar exposure, so it carries bitcoin exposure at roughly half the volatility. Anyone can buy, sell and hold BTCD; whitelisted partners mint and redeem it at the fair price. It suits AMM liquidity and lending collateral.
* [**sBTCD**](/tokens/sbtcd.md) is staked BTCD. Yield is paid into the sBTCD vault, so each sBTCD represents more BTCD over time. Holding BTCD and holding sBTCD carry the same exposure; they differ in yield and liquidity.
* [**FISC**](/tokens/fisc.md) is the governance token.

## How yield reaches stakers

The engine pays yield only from surplus, in newly minted BTCD. Every asset in the reserves earns, but only staked BTCD is paid, so the share that would belong to unstaked BTCD is redirected to stakers. See [Collateral ratio and yield](/how-the-engine-works/collateral-ratio-and-yield.md).

## Vault receipt tokens

| Token     | Vault                                                                  | Documentation                                               |
| --------- | ---------------------------------------------------------------------- | ----------------------------------------------------------- |
| **bdUSD** | USD Vault: 2× sBTCD against 1× wBTC debt, so BTC exposure nets to zero | See [USD Growth](/opportunities/usd-growth.md)              |
| **bdBTC** | BTC Vault: 2× sBTCD against 1× USDC debt, one-for-one BTC exposure     | Proposed design: [BTC Growth](/opportunities/btc-growth.md) |
| **BTCdc** | wBTC Carry Vault: wBTC collateral, USDC borrowed into bdUSD            | See [wBTC Carry Vault](/opportunities/wbtc-carry-vault.md)  |

Vault depositors hold the vault's receipt token, not BTCD.