---
# System prepended metadata

title: 'Nomination pools free balance '

---

## Nomination pools free balance & TVL

- [ ] Why is there available balance (free - locked) in some Polkadot/Kusama pools?
- [x] Is TVL correctly calculated?


### Available balance on nomination pools bounded accounts

- **Join pool**: When a member joins the pool, the member's balance is transferred to the pool's bonded account and bonded immediately (i.e. it becomes locked in the pool's bonded account).
    - member transfers bonding `amount` to pool's bonded account
    - call `T::Staking::bond_extra(bonded_account, amount)` to bond extra on pool's bonded account in staking
    - --> no new `available_balance` in the pool's bonded account
- **Rewards**
    - Rewards are paid to `pool.reward_account`, thus the bonded pool balance should not be affected by rewards/commissions (unless `reward_pool_account == bonded_pool_account`, which is never the case).

### Is TVL correctly calculated?

It may get out of sync due to implicit withdraw on the staking side, see https://github.com/paritytech/polkadot-sdk/pull/3052 for more info.