Super Staker

A super staker is a node on the Qtum blockchain that stakes coins on behalf of other holders through Qtum's offline staking feature. Holders delegate their addresses to the super staker, which uses the coins in those addresses as stake when competing to produce blocks and keeps an agreed percentage of the rewards as its fee. The coins never leave the delegators' own addresses.

The role is specific to Qtum, a Proof of Stake (PoS) network that combines Bitcoin-style Unspent Transaction Outputs (UTXOs) with an Ethereum Virtual Machine (EVM)-compatible smart contract layer. A super staker is comparable to a Tezos baker under Liquid Proof of Stake (LPoS) or a pool operator in delegated staking, but unlike most staking pools it never takes custody of anyone's coins. It also differs from a masternode, which must lock a fixed collateral and provide extra network services.

Think of a taxi company that drives cars owned by other people. Each owner keeps the logbook and the spare key and can take the car back whenever they like. While the car is on the road, the company does the driving, pays for the fuel and keeps a fixed share of each fare; the rest goes to the owner.

A super staker is the taxi company. It runs the always-on computer and does the staking work. The delegators are the car owners: their coins earn rewards without leaving their hands, and the super staker is paid only for the work it does.

According to Qtum's documentation, a super staker is an ordinary Qtum Core wallet started in super-staking mode, either with the -superstaking option on the qtumd daemon or through the settings of the Qtum-Qt desktop wallet. The operator then sets its terms:

• Minimum fee. The lowest percentage of each reward the staker will accept. A delegator chooses the fee when delegating, and the staker ignores delegations below its minimum.
• Minimum UTXO size. The smallest coin output it will stake, 100 QTUM by default. Smaller delegated outputs are left aside.
• Acceptance list. Whether to accept all delegations, only those on an allow list, or all except those on an exclude list.

The super staker must also hold some QTUM of its own. Qtum's documentation notes that a super staker needs UTXOs of its own to commit to stakes, so an operator cannot run one with delegated coins alone. Qtum-Qt can run several super-staker addresses with different fees, while qtumd applies one fee and one minimum size to all of them.

Delegations are recorded through calls to a built-in delegation contract, so anyone can see on-chain which addresses are delegated to which staker. When a delegated UTXO wins a block, the protocol pays the block's reward according to the agreed split.

A super staker earns its fee share on every block won with delegated coins, plus full rewards on blocks won with its own coins. Its share of one block's reward can be written as:

• $F$ is the fee the super staker keeps.
• $R$ is the total reward for the block won by a delegated UTXO.
• $f$ is the agreed fee rate, written as a decimal.

Worked example: with an illustrative reward of 1 QTUM and a 10% fee, the super staker keeps $1 \times 0.10 = 0.1$ QTUM, and the delegator receives $1 - 0.1 = 0.9$ QTUM. Against that income, the operator pays for a reliable server, its own coins tied up as stake and the time needed to keep the node updated and online. A super staker that is offline wins nothing, for itself or its delegators.

Because the delegator keeps custody, the main risks are lost rewards rather than lost coins. Delegators typically compare:

• Fee level. A lower fee leaves more reward, but a staker that lowers its fee later only applies the new rate after the delegator redelegates.
• Uptime and track record. A staker with long, reliable operation is more likely to keep winning blocks.
• Size. A very large staker concentrates network power, which reduces decentralization; spreading delegations among smaller stakers supports a healthier network.

Critics of delegation models note that a handful of large stakers can end up controlling much of the stake, a pattern seen across PoS networks with validators and pools. Qtum does not slash super stakers in the way some chains penalize misbehaving validators, so their main incentive to behave is reputation and fee income. For holders who prefer to run their own setup, solo staking remains possible with a full node, and a node operator with enough coins can become a super staker itself. Like other forms of staking, the rewards consist mostly of newly issued coins, so they add to supply under the network's tokenomics.

• Qtum documentation: Offline Staking
• Qtum