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Bitcoin supply, halving and fees

The first transaction in a block, called the coinbase transaction, lets the miner claim the permitted subsidy and transaction fees.

IntermediateContent revised · 13.09.20263 min reading · allow 5–10 more minutes for the workshopBlockAxis

Your learning plan

Separate issuance from miner income

By the end, explain the diagram in your own words, solve the case and justify the correction.

Prerequisites : Bitcoin mining and difficulty

Level 2 · Intermediate →

Reading path · 6 / 35 · Intermediate

Key takeaway

The first transaction in a block, called the coinbase transaction, lets the miner claim the permitted subsidy and transaction fees.

The essentials

The first transaction in a block, called the coinbase transaction, lets the miner claim the permitted subsidy and transaction fees. It need not involve the company sharing that name. The subsidy halves every 210,000 blocks; calendar dates are estimates.

How it works

The scheduled issuance approaches slightly less than 21 million BTC. Lost funds remain in the record but may never be spendable again. Maximum supply, issued supply and economically available supply therefore measure different things. Market capitalisation usually uses an estimated circulating quantity rather than counting every recoverable coin.

What to watch

As subsidies shrink, fees become a more important source of miner revenue. Long-term security depends partly on demand for block space and production costs. Programmed scarcity does not establish a market price, ensure liquidity or guarantee investment returns. Evaluate the monetary rules separately from assumptions about future demand.

Understand the details

The block subsidy introduces new bitcoin according to consensus rules, while transaction fees transfer existing bitcoin. A miner’s gross block revenue combines both. Halving reduces the subsidy at a specified block-height interval; it does not halve user balances or mechanically double the market price. Calendar estimates depend on actual block production.

Boundaries and common mistakes

A supply rule is not a forecast of demand. Lost keys can make coins inaccessible without deleting their historical issuance. Miner profitability also depends on energy, equipment, financing and competition. Long-term security discussions must distinguish protocol accounting from uncertain future market conditions.

The mechanism at a glance

  1. Subsidy: new coins
  2. Fees: existing coins
  3. Combined block revenue
  4. Costs determine profit
Separate issuance from miner income. Conceptual map: read these four landmarks together with the explanation above.
Applied workshop · work at your own pace

Apply the lesson to a case

In a fictional system, a block pays a subsidy of 4 units and fees of 1 unit. After a halving, assume fees remain 1. Build a before/after table for new issuance, transferred fees and total producer revenue. These numbers are illustrative, not Bitcoin’s current subsidy.

Does total revenue halve in this example?

Choose one answer.

Prepare a correction note

Describe the passage and the proposed correction. This creates a local note for you to share; it sends nothing. Do not include personal or confidential information.