The biggest decentralization move bitcoin mining has seen in years came quietly, with seven of the largest groups agreeing to support the same open standard.
Foundry, AntPool, F2Pool, SpiderPool, MARA Pool, Block Inc and DMND have joined the Stratum V2 working group, the group announced last week.
Stratum V2 is an open source protocol that governs how mining pools communicate with individual miners in those pools. The biggest practical change it introduces is allowing individual miners to build their own block templates, meaning that the choice of which transactions are included in each new block falls to the miner and not whoever operates the pool.
Foundry alone controls 34.2% of the global bitcoin hashrate, AntPool another 14.2%, F2Pool 11.3% and SpiderPool 10.5%, with MARA Pool adding 4.7%, according to Hashrate Index data. Along with the rest of the Stratum V2 signatories, the seven groups now supporting the standard represent about 75% of the entire bitcoin hashrate.
Under the current Stratum V1 standard, transaction selection for almost every new block falls to the pool operators rather than the individual miners who actually do the work. That concentration has been the loudest structural concern about modern mining over the past two years.
Stratum V2 doesn’t change the hashrate concentration, but it does change who decides what goes into each block, which is the part that really worries the Bitcoin community.
A single group controlling more than 30% of the hashrate is not ideal, since the same group that decides the order of transactions for that part of the blocks is the real risk that people point out.
The protocol has been around since 2022, when Braiins and Spiral co-founded the working group. Until now it had been treated as a niche side project with limited adoption. The merger of Foundry and AntPool gives it real scope, and the working group frames the move as the start of a new phase of accelerated implementation.
The timing also coincides with what the mining sector in general is facing. CoinShares estimates that up to 20% of miners are currently unprofitable, with a hash price (the income a miner earns per unit of computing power) of $38.57 per petahash per second per day, at or near break-even for operators running mid-generation hardware.
The difficulty will increase again on May 15 from 132.47T to 135.64T, according to CoinWarz. The network hash rate now stands at 998 exahash per second.
