Three mining pools produced about 61% of Bitcoin blocks in the seven days through Sunday, according to a live ranking derived from Mempool block data. The November 15 snapshot put Foundry USA first with 24.3% of attributed blocks, followed by AntPool at 19.7% and F2Pool at 16.7%. The three shares add to 60.7%, leaving the remaining blocks divided among more than a dozen other identified pools and a small unattributed category.

A separate 30-day dataset shows the same ranking

CryptoKeyhole's independently maintained Bitcoin node counted 4,099 blocks in the 30 days to November 15. It attributed 1,049 blocks, or 25.6%, to Foundry USA, with AntPool at 19.6% and F2Pool at 16.8%. That places the same three pools at roughly 62% over the longer window. Exact percentages differ because the services use different observation periods, update times and attribution methods, but both datasets show the same order and a combined share above three-fifths.

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Pool concentration is not the same as miner ownership

A mining pool coordinates work and distributes rewards among participating miners. Bitcoin's developer guide explains that pool members submit shares proving contributed work, while the pool sends qualifying blocks to the network and pays miners according to its reward system. The companies and farms supplying the computing power can redirect machines to another pool. A pool's block share therefore does not mean the operator owns the same share of global hardware or electricity use.

The operator still occupies an important coordination point

The distinction does not make pool distribution irrelevant. In conventional pooled mining, the operator commonly supplies the block template or transaction set that miners work on, validates submitted shares and handles payouts. Concentration can therefore matter for transaction-selection policy, operational resilience and the number of independent coordinators needed to produce a majority of recent blocks. The current readings do not prove that the three largest pools coordinate with one another, control their members' machines or could sustain the same share if miners chose to leave.

Weekly figures also contain statistical noise

Block discovery is probabilistic. A pool can find more or fewer blocks than its underlying computing share would imply over a short period, sometimes described as mining luck. Simple Mining's explanation of the Mempool-derived table notes that rankings change as hashpower migrates and daily shares fluctuate. Attribution services also infer a pool from identifiers in mined blocks, so an unknown or changed tag can alter classifications without changing physical hashpower. That is another reason to compare providers rather than trust one table. The agreement between the seven-day and 30-day rankings makes the concentration pattern more informative than a single-day reading, but it still should not be treated as a permanent allocation of network power.

What to watch next

Foundry remained the largest pool without reaching 25% in the weekly snapshot, while F2Pool held a clear third place near 17%. Future readings will show whether those shares persist after additional difficulty periods or revert as luck and miner routing change. A meaningful shift would require more than one moving weekly table: it would appear across longer observation windows and independent block-attribution services. For now, the verified conclusion is limited but material: three pool operators were associated with just over 60% of recently produced Bitcoin blocks.

Sources

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