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

# stUsdc

## Overview

Staked USDC is an rebasing auto-compounding LST for Circle's USDC and Bloom TBYs. The interface below is only available for the Arbitrum deployment of the protocol. 

## Contract API

### `depositTby`

```solidity
function depositTby(uint256 id, uint256 amount) external returns (uint256 amountMinted);
```

Deposit a specified `amount` of `TBY`s to mint `stUsdc`.

### `depositAsset`

```solidity
function depositAsset(uint256 amount) external returns (uint256 amountMinted);
```

Deposit a specified `amount` of `underlyingToken` to mint `stUsdc`.

### `redeemStUsdc`

```solidity
function redeemStUsdc(uint256 amount) external returns (uint256 underlyingAmount);
```

Redeem `stUsdc` in exchange for `underlyingTokens`

### `poke`

```solidity
function poke(LzSettings calldata settings) external;
```

Invokes the auto stake feature as well as updates the value accrual.

### `wstUsdc`

```solidity
function wstUsdc() external view returns (IWstUsdc);
```

Returns the `wstUsdc` contract instance.

### `asset`

```solidity
function asset() external view returns (IERC20);
```

Returns the `underlyingToken` contract instance.

### `stakeUpStaking`

```solidity
function stakeUpStaking() external view returns (IStakeUpStaking);
```

Returns the `StakeUpStaking` contract instance.

### `performanceBps`

```solidity
function performanceBps() external view returns (uint256);
```

Returns the performance Bps variable. 

### `lastRedeemedTbyId`

```solidity
function lastRedeemedTbyId() external view returns (uint256);
```

Returns the last redeemed `tbyId`.

### `globalShares`

```solidity
function globalShares() external view returns (uint256);
```

The total shares of `stUSDC` tokens in circulation on all chains.