Bitcoin (BTC) is commonly praised as essentially the most decentralized cryptocurrency by its supporters, however the fact could possibly be one thing else. Onchain information exhibits that solely two Bitcoin mining swimming pools mined over 51% of all BTC within the final three years. Right here is why it issues and will elevate a centralization alert for the main blockchain community.
Finbold retrieved this info from mempool.house, a Bitcoin information aggregator and block explorer, gathered instantly from an observer node. Basically, this information ranks Bitcoin mining swimming pools per their mined blocks towards the entire blocks mined in a sure interval.
Within the final three years from March 28, 2025, the Bitcoin mined blocks had been extremely dominated by two mining swimming pools.
Exactly, Foundry USA printed 46,076 blocks (28.72%) and AntPool 34,365 blocks (21.42%), out of 160,432. Collectively, these mining swimming pools have mined 90,441 blocks, or 56.37% of the entire, within the final three years.

Why does it matter to have solely two mining swimming pools above the 51% threshold
In line with the whitepaper written by Satoshi Nakamoto, Bitcoin’s worth proposition lies in reaching consensus over the blockchain state in a decentralized method. That is achieved by way of Bitcoin mining, when particular nodes (the miners) use computational energy to crack cryptographic hashes, discovering blocks.
As soon as the blocks are found, the miner features the precise to gather the coinbase, that are newly created BTC items. Apart from the coinbase, miners can even add transactions to the blocks, amassing their respective charges.
For that, the miner must broadcast the found block with each their coinbase transaction and all of the third-party transactions. Different nodes, as designed by Satoshi, will observe the longer chain, which suggests the chain with extra proof-o-work connected to it, or extra added blocks.
There’s a theoretical assault referred to as the 51% assault, which, theoretically, may enable a foul actor to make double spends. Furthermore, Bitcoin mining swimming pools may intentionally censor transactions from being broadcasted, in the event that they management sufficient of the mined blocks.
Finbold reported a case the place F2Pool, the third-largest Bitcoin mining pool, was caught – and later admitted – filtering transactions.
At its present state, the Bitcoin community has a Nakamoto Coefficient of two. The Nakamoto coefficient is a metric that measures the decentralization of a blockchain community by figuring out the minimal variety of impartial entities (like miners) wanted to manage or disrupt the community.
Bitcoin mining swimming pools and never particular person miners or nodes
Whereas every pool is supposedly made of various miners, it’s the pool coordinator, a single entity, accountable for setting the block, broadcasting it to the community, amassing the rewards, after which, if they need, distribute it to their miners.
Due to this fact, the mining swimming pools are the related entities when measuring the present blockchain consensus decentralization state. Not the person miners or nodes, that may migrate solely as soon as it’s too late, beneath a hypothetical assault.
We’ve additionally seen instances the place transaction charges weren’t distributed to AntPool miners, as anticipated, however despatched again to the sender.
Moreover, AntPool was additionally the protagonist of one other discovery by the famend pseudonym analyst b10c. In line with the researcher, information suggests the second-largest mining pool may have sturdy affect over 5 different Bitcoin mining swimming pools.
Trying on the merkle branches that mining swimming pools ship to miners as a part of stratum jobs, it is clear that the BTCcom pool, Binance pool, Poolin, EMCD, Rawpool, and probably Braiins* have precisely the identical template and customized transaction prioritization as AntPool. https://t.co/KTjFWtTXEP pic.twitter.com/xhCrdvkOH8
— b10c (@0xB10C) April 17, 2024
In conclusion, Bitcoin decentralization could possibly be in verify as economies of scale dynamics play out, growing large miners’ dominance. The extra blocks a mining pool discovers, the extra rewards it collects from newly issued BTC and transaction charges. This permits for bigger investments in infrastructure, simpler entry to capital, and much more dominance over future block mining.
Featured picture from Shutterstock.

