FTM staking mechanics

FTM Liquid Staking lets the user stake their funds through the corresponding smart contracts on the Fantom network, accumulate rewards, and receive their stake and rewards when unstaking.

The following section explains staking requirements, fees, rewards, validators, smart contracts and function calls to interact with these smart contracts.

Requirements

The requirements when staking are:

• Minimum value to stake (minimumStake) — 1 FTM.

• Maximum value to stake — unlimited, at the user’s discretion.

The requirements when unstaking are:

• Minimum value to unstake — from 0 FTM.

• Maximum value to unstake — staked amount + % of the reward, up to the user’s balance.

• Release time — depending on the amount in the unstake request, it can take different number of validator's lock-up periods. Each time a lock-up period ends, Ankr claims all rewards for all stakes from a validator. It means if the user wants to unstake a small amount like 1 FTM, their request will likely fit rewards claimed at the end of the current validator's lock-up period, so in 1 to 35 days. However, if the user wants to unstake 10000 FTM, the request amount is unlikely to fit the current claimed rewards and will have to wait until Ankr has enough funds to fulfill the unstake request.

Fees

When staking, the user pays no technical service fee.

Unstaknig applies a burnFee that depends on the current liquidity and amount to unstake, and is calculated by the FantomPool smart contract. The fee is deducted from the withdrawn amount.

The user must also count in the gas price for outgoing transactions.

Rewards

Validators receive rewards on the regular basis. The exact time is to be updated soon.

The APY is dynamic and calculated from the validators' rewards.

Validators

The validator set consists:

• Fantom Foundation validator (opens in a new tab)
• MCLB-DAO validator (opens in a new tab)
• Ankr validator (opens in a new tab)

For the lock-up period affecting release time of funds in unstake requests, see the "Release time" explanation in Requirement.

Smart contracts

Smart contracts and addresses involved in FTM Liquid Staking are:

• FantomPool (opens in a new tab) — contract on Fantom Chain where the user sends their initial staking or unstaking request.
• aFTMb (opens in a new tab) — contract on Fantom Chain that mints or burns aFTMb tokens for the user in 1:1 ratio with the staked amount.
• ankrFTM (opens in a new tab) — contract on Fantom Chain that mints or burns ankrFTM tokens for the user in the amount defined by the current FTM–ankrFTM ratio (opens in a new tab).
• FantomStub — contracts (curr. val. — 47) that delegates stakes to a validator from the validator set. The contracts are needed to avoid Fantom intrinsic restrictions. The addresses are not listed, as the user never directly interacts with these contracts.
• Operator address (opens in a new tab) — address of the Ankr backend on Fantom Chain that:
  • When unstaking, receives the unstaked funds+rewards to send to stakers.

Smart contract code can be viewed by following the links and selecting the Contract tab.

Staking workflow

The workflow is both user and Ankr-driven. The user part is Step 1, the Ankr part is Steps 2–3.

1. User calls the function FantomPool::stake() payable on the Fantom network. The function is payable, so the user needs to specify the amount to stake. The amount must meet the minimumStake requirement, which is returned by the function FantomPool::getMinimumStake() public view returns (uint256).

2. If the transaction is successful, aFTMbs are automatically minted to the user’s address. Also an event FantomPool::StakeReceived(stakerAddressIndexed, amountMinted) is emitted. The event can later be found using the stakerAddressIndexed parameter. User can later look up their aFTMb balance in the aFTMb contract.

3. Then the Ankr backend sends the staked funds to the FantomStub contract and delegates the funds to a validator from the validator set to gain rewards. The validator set consists of one Fantom (opens in a new tab), one MCLB-DAO (opens in a new tab), and one Ankr (opens in a new tab) validator.

4. Currently, the Ankr backend does not monitor events on the blockchain, but instead uses cron for scheduled checks: once an hour for funds, delegating, updating ratio, etc.

Unstaking workflow

The workflow is both user and Ankr-driven. The user part is Step 1, the Ankr part is Steps 2–3.

1. User calls aFTMb::function burn(uint256 amount).

2. If the transaction is successful, aFTMbs are automatically burned and removed from the user’s address. An event TokensBurned(address indexed account, uint256 amount, uint256 shares, uint256 burnFee, uint256 indexed wrId) is emitted, and the user receives amount - burnFee FTM within the period of up to 35 days. The fee depends on unstaked amount and can be shown to the user via getBurnFee(uint256 amount) external view returns (uint256), which changes from time to time based on the current available liquidity.

3. Then FantomPool saves the request in the form of a WithdrawalRequest {address payable staker; uint256 amount;} struct. Within up to 35 days the Ankr backend calls withdrawLast() to send the staked funds back to the user, and a Withdrawn(address indexed staker, uint256 amount, uint256 indexed wrId) event is emitted.