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Block Reward

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What Is The Block Reward?

What Is The Block Reward?

The block reward is how Bitcoin miners are compensated for mining and adding blocks of transactions to the blockchain. The block reward is made up of two parts: the block subsidy and transaction fees commonly known as miner fees.

The block reward fluctuates all the time. The block subsidy is fixed and predictable but transaction fees fluctuate based on the demand for limited on-chain block space.

Coinbase Transaction

A coinbase transaction is the first transaction found in every bitcoin block. It is referred to as a “coinbase” because, much like the way mining gold requires a “base” or starting point, this transaction marks the beginning of new coins being generated. The block subsidy, which consists of the newly created coins, along with all of the accumulated miner fees for that block, goes into this transaction, making it unique. This transaction doesn’t have the typical inputs that are usually found in standard transactions and has only one output.

It’s important to note that the coinbase transaction is not related to the San Francisco based altcoin exchange named “Coinbase”.

You can view the block reward in the first transaction in every block. Here in this transaction 5b130edc8f392c17dc6aff22187d232c3997db0c33790c8a91c202659936d051 the reward for mining this particular block is 6.31084793 bitcoin.

The Block Subsidy

The Block Subsidy is the generation of new bitcoin in every block and the primary means of compensating Bitcoin miners for proof of work.

When Bitcoin first began, the block subsidy was 50 bitcoin per block but the subsidy is reduced by 50% every 210,000 blocks in an event commonly known as The Halving.

With the total supply of bitcoin hard-capped at 21,000,000 bitcoin, the block subsidy will eventually come to an end sometime around 2140 when all of the bitcoin has been mined.

Once the final sats have been mined, transaction fees will become 100% of the block reward and the only compensation for Bitcoin miners.

Transaction Fees

Transaction fees are the financial incentive for bitcoin miners to confirm transactions and add them to the blockchain. When transactions are initially sent, they wait in the MemPool until a miner decides to add them to a block. Since miners have a financial incentive to maximize revenue, transactions with the highest fee rate are prioritized and transactions with a lower fee will be added as soon as block space becomes more available.

Transaction fees perform several functions. They prevent “spam” transactions by introducing a cost to use the network. Fees prioritize transactions by giving the sender the ability to set their own fee and wait for it to be added by the miners. Fees are also what makes bitcoin transactions censorship resistant because the sender of any given transaction can increase the fee until a miner adds it to a block.

While the block subsidy is currently the majority of the block reward, transaction fees will become the dominant form of compensation for bitcoin miners in the future.

Increasing Fees and Decreasing Subsidy

As the block subsidy decreases with each halving, transaction fees will slowly become the majority of the block reward and the primary means of rewarding miners for adding blocks of transactions to the blockchain.

As soon as the final sats are mined sometime in 2140, the block subsidy will come to an end and transaction fees will account for 100% of the block reward.