Immutable Variables

# Handle

hickuphh3


# Vulnerability details

### Impact

The following variables can be made immutable to save gas.

TokenFactory.sol

- `longShort`

SyntheticToken.sol

- `longShort`
- `staker`
- `marketIndex`
- `isLong`

YieldManagerAave.sol

- `longShort`
- `treasury`
- `paymentToken`
- `aToken`
- `lendingPool`
- `aaveIncentivesController`
- `referralCode`

