The block reward is the incentive that drives miners worldwide to spend billions of dollars on equipment and electricity to secure the Bitcoin network. But what exactly does it consist of? It’s not a single amount, but a combination of two different components: the block subsidy and transaction fees. Understanding this structure is critical for assessing the long-term profitability of mining.
Block Subsidy: Creating New Coins
The block subsidy is the primary and most well-known part of the reward. These are entirely new coins that are “minted” by the network at the moment a block is created and credited to the miner who found it. This is the part of the reward that halves every four years during an event known as halving.
- Purpose: To incentivize network participation in the early stages and ensure a predictable issuance of new coins.
- Feature: This is a temporary mechanism. Around 2140, when 21 million BTC have been mined, the subsidy will become zero.
As of today (after the 2024 halving), the subsidy for one block is 3.125 BTC. This constitutes the lion’s share of miners’ income.
Transaction Fees: Payment for Block Space
The second component of the reward is the sum of all fees that users have attached to the transactions included in that block. When you send bitcoins, you can add a small “charge” (fee) to motivate miners to include your transaction in the next block as soon as possible.
Imagine a block as a cargo container with limited space. A miner, when forming this “container,” will primarily take those “packages” (transactions) for which senders offer the highest fee.
- Purpose: To create a market for block space and provide a long-term incentive for miners after the subsidy runs out.
- Feature: The amount of fees is not fixed. It depends on network congestion: the more people want to process transactions, the higher the competition for block space and thus the higher the fees.
The Future of Income: Why the Role of Fees is Growing?
With each halving, the block subsidy decreases, meaning its share of miners’ total income declines. At the same time, the role of fees is steadily growing. The day will come when miners’ income will be 100% composed of transaction fees.
This is an economic model embedded in the protocol that ensures the long-term viability of the network:
- In the early stages, when the network was little-known and transactions were few, a high subsidy ensured security.
- As popularity and the number of transactions grow, increasing fees gradually replace the decreasing subsidy.
This means that Bitcoin’s long-term security directly depends on whether people are willing to pay fees for using the network. During periods of high activity, for example, during the launch of new Bitcoin-based projects (like Ordinals), we have already seen how the sum of fees in some blocks exceeded the size of the subsidy. This gives confidence that the economic model is working.
Thus, when you look at mining income, you see the result of two forces combining: the predictable and decreasing subsidy and volatile, but potentially growing, fees. Understanding this balance is key to assessing the future of the entire industry.
