# Bitcoin Mining Pools: Hashrate Share by Pool

> Bitcoin mining pools ranked by blocks found and implied hashrate share over a day, a week and a month, with concentration measures and unidentified blocks.

Markdown copy of https://voltfincrypto.com/apps/bitcoin-mining-pool-share

**Question:** Which mining pools found the most Bitcoin blocks this week?

- Kind: Dashboard in Voltfin Vantage
- Topic: [Bitcoin](https://voltfincrypto.com/topics/bitcoin)
- Chains: Bitcoin
- Status: Planned. The data is not published yet, so this page states no figure; each figure will open its receipt when it is.

The mining pools that found the most Bitcoin blocks this week are ranked here by blocks found, with the hashrate share each implies, over a day, a week and four weeks of blocks. Pools are identified from the tag each writes into its coinbase transaction and from the addresses it pays, so the ranking rests on the blocks themselves.

Block counts are a noisy measure of hashrate: a pool with a steady share still has lucky and unlucky weeks, so the dashboard sets longer windows beside shorter ones. A pool is not a miner either. Many independent miners point their machines at each pool and can switch quickly, which matters when reading concentration. Blocks whose tag and payout match no known pool are shown as unidentified, not spread across the others.

## Blueprint

### Pool share

Blocks and implied hashrate by pool over the selected window.

- **Pools that found blocks** (count): Distinct pools that found at least one block in the window, from coinbase tags and payout addresses.
- **Largest pool's share** (%): The share of the window's blocks found by the pool with the most blocks.
- **Top three pools' share** (%): The combined share of the window's blocks found by the three pools with the most blocks.
- **Unidentified blocks** (%): The share of the window's blocks whose tag and payout match no pool in the registry.
- **Blocks by pool** (blocks): Blocks found per pool in the window, with the smallest pools grouped together.
- **Every pool**: Each pool with its blocks in the window, share of blocks, implied hashrate and the height of its latest block.

### History

How pool shares and concentration moved over time.

- **Pools needed for half of blocks** (count): The smallest number of pools whose combined share reaches half of the last four weeks' blocks.
- **Concentration index**: The Herfindahl index of pool shares over the last four weeks of blocks, from near zero when spread out to one for a single pool.
- **Pool shares by week** (%): Each pool's weekly share of blocks over the selected period, the largest pools shown and the rest grouped.
- **Concentration over time**: The Herfindahl index and the top three pools' combined share by week over the selected period.

Filters: Window (Blocks of the last day, the last week or the last four weeks); Period (Last 90 days, last year or last four years).

## How it will be measured

- Each block's coinbase transaction is read with getblock verbosity 2; the pool is identified from the text tag in its input script and from its payout addresses, matched against a registry of published pool tags.
- Blocks per pool are counted over the last day, week and four weeks of blocks; a pool's implied hashrate share is its share of the blocks in that window.
- Implied hashrate per pool multiplies its block share by the network hashrate estimated for the same window from difficulty and block times.
- Concentration is reported as the combined share of the largest pools and as a Herfindahl index of pool shares, and every figure is pinned to the window's last block.

## Data it needs

- `bitcoin_network_daily` (to build): Blocks, hashrate implied by difficulty, difficulty, fees, transaction counts, block weight and miner revenue (subsidy plus fees) per day.
- `address_labels` (to build): Labels for known addresses: exchanges, bridges, protocols, funds, treasuries, sanctioned addresses and known attackers.
- Source: getblock verbosity 2 for every block: the coinbase input script and output addresses
- Source: A registry of published pool coinbase tags and payout addresses, each with its source
- Source: Network hashrate for the same window, from difficulty and block times

## Questions

### What is a Bitcoin mining pool?

A service that combines the hashrate of many miners, builds the block templates they work on and shares the rewards by each miner's contributed work. Pooling smooths miners' income, since a single miner might wait a very long time to find a block alone.

### How do you know which pool mined a block?

Most pools write a recognizable tag into the coinbase transaction and pay rewards to known addresses. The dashboard matches both against a registry of published tags and addresses; a block that matches nothing is counted as unidentified.

### Is Bitcoin mining too concentrated?

Pool shares show who builds block templates, which is what matters for transaction selection and censorship. The hardware itself is spread across many miners who can leave a pool, so pool shares overstate control of hashrate. The dashboard reports the top pools' combined share and a concentration index and leaves the judgment to the reader.

### What is a 51 percent attack?

An attack in which one party controls more hashrate than the rest of the network combined, letting it reorder or censor recent blocks and double-spend its own transactions. It cannot create coins from nothing or spend other people's coins.

### Why do mining pool shares change from week to week?

Partly luck: finding blocks is random, so a pool's weekly count varies around its real share. Partly movement: miners switch pools over fees, payout terms and outages. Longer windows smooth out the luck, which is why the dashboard shows four weeks beside one.

## Glossary

- **Coinbase tag**: Text a pool writes into its coinbase transaction's input script, usually the pool's name.
- **Block template**: The set of transactions and header fields a pool hands its miners to hash. Whoever builds the template chooses the transactions.
- **Herfindahl index**: A concentration measure: the sum of each pool's squared share. Higher values mean block production sits with fewer pools.

## Related apps

- [Bitcoin Hashrate and Mining Difficulty](https://voltfincrypto.com/apps/bitcoin-hashrate-difficulty)
- [Bitcoin Hashprice and Miner Revenue per Day](https://voltfincrypto.com/apps/bitcoin-miner-revenue-hashprice)
- [Next Bitcoin Difficulty Adjustment Estimate](https://voltfincrypto.com/apps/bitcoin-difficulty-adjustment-estimate)
- [Ethereum Block Builders: Market Share of Blocks](https://voltfincrypto.com/apps/ethereum-block-builders)
- [Bitcoin Halving Countdown and Block Reward](https://voltfincrypto.com/apps/bitcoin-halving-countdown)
- [Bitcoin Transaction Fees and Mempool Tracker](https://voltfincrypto.com/apps/bitcoin-fees-mempool-tracker)

Build it in Voltfin Studio: https://app.voltfincrypto.com/signup?next=%2F