Seven of the world's largest Bitcoin mining pools have quietly joined forces behind a single open protocol that shifts one of mining's most consequential decisions — which transactions go into each new block — away from pool operators and back to the individual miners doing the work. The move represents the most significant decentralization development in Bitcoin mining in years.
Foundry, AntPool, F2Pool, SpiderPool, MARA Pool, Block Inc, and DMND have all joined the Stratum V2 working group, the group announced last week. Together they represent close to 75% of all Bitcoin hashrate globally.
What Stratum V2 actually changes
Stratum V2 is an open-source protocol that governs how mining pools communicate with the individual miners contributing computing power to those pools. The current standard, Stratum V1, hands transaction selection entirely to pool operators — meaning the pools themselves decide which transactions are included in each new block, not the miners performing the actual work.
Stratum V2 flips that arrangement. It allows individual miners to construct their own block templates, putting transaction selection decisions in the hands of the people running the hardware rather than whoever operates the pool. Hashrate concentration does not change — Foundry still controls 34.2% of global hashrate, AntPool 14.2%, F2Pool 11.3%, and SpiderPool 10.5% — but the critical question of who decides what goes into each block shifts fundamentally.
That distinction matters more than the hashrate numbers suggest. A single pool controlling 30% or more of global hashrate is a concern for Bitcoin's decentralization, but it becomes a more acute concern when that same pool also controls the transaction ordering for its entire share of blocks. Stratum V2 addresses the second problem directly, even if the first remains unchanged.
From niche project to industry standard
The protocol has existed since 2022, when Braiins and Spiral co-founded the Stratum V2 working group. For three years it was treated largely as a niche side project with limited real-world adoption. The addition of Foundry and AntPool — the two largest pools in the world by hashrate — changes that calculus entirely. The working group described the new memberships as the start of an accelerated deployment phase rather than a continuation of the slow-adoption period that preceded it.
The Bitcoin community has raised concerns about centralized transaction selection for at least the past two years. The timing of seven major pools aligning behind a common solution suggests those concerns have finally reached a threshold where the industry felt compelled to act collectively.
The economic backdrop: a stressed mining cohort
The announcement arrives as Bitcoin miners are navigating some of the toughest economics since the last halving cycle. CoinShares estimates that up to 20% of miners are currently operating unprofitably, with hashprice — the revenue a miner earns per unit of computing power — sitting at $38.57 per petahash per second per day, at or near breakeven for operators running mid-generation hardware.
Network difficulty is set to rise again on May 15 from 132.47T to 135.64T according to CoinWarz, adding further pressure to margins already stretched thin. Total network hashrate now sits at 998 exahash per second — a figure that reflects continued investment in mining infrastructure even as near-term profitability has compressed.
In that environment, a protocol that gives individual miners more control over their revenue-generating activity — and reduces their dependence on pool operator decisions — has practical economic appeal beyond its decentralization benefits. Miners who can select higher-fee transactions for their own block templates have a direct financial incentive to adopt Stratum V2, independent of any ideological commitment to decentralization.
What comes next
The working group framed last week's announcement as the beginning of a new phase rather than a completed transition. Adoption at the pool level does not automatically mean individual miners immediately begin constructing their own block templates — that requires hardware compatibility, software updates, and deliberate choices by miners to opt into the new system.
But with pools representing 75% of global hashrate now formally committed to the standard, the infrastructure for the shift is in place. Whether individual miners move quickly to take advantage of the transaction selection capabilities Stratum V2 unlocks will determine how much of the protocol's decentralization promise is realized in practice — and how quickly.
For Bitcoin, the broader significance is straightforward: the network's most structurally important upgrade to mining governance in years just happened, and it happened without a contentious fork, a protocol war, or a community split. Seven pools, one standard, and a quiet announcement.
Jasper
Davin
Hui Xin
Joy