In a landmark move for the Bitcoin mining industry, seven of the largest mining pools have officially joined the Stratum V2 Working Group this week. Antpool, F2pool, Foundry, Spiderpool, Block Inc., MARA Foundation, and DMND are now part of the effort to advance the open mining protocol standard, signaling the clearest shift yet toward miner-controlled transaction selection.
Stratum V2: A Revolutionary Upgrade to the Mining Protocol
Stratum V1, introduced in 2012 by Marek "Slush" Palatinus, became the de facto industry standard but was never designed as a formal specification. It left pools with full control over transaction selection, operated in plaintext, and exposed miners to hashrate hijacking and surveillance. The V2 protocol addresses these critical issues.
According to the official announcement, Stratum V2 employs authenticated end-to-end encryption, reduces bandwidth usage by approximately 60% on the pool side and 70% for miners, and introduces a Task Declaration sub-protocol that allows miners to create their own block templates instead of accepting what pools assign. This means miners can independently select transactions, optimize fee collection, and truly own the content of blocks.
Real-world testing by Braiins shows that miners can achieve up to 7.4% higher profitability through faster block template delivery, lower latency, and better fee selection when running V2 natively.
Seven Pools Unite, Heavyweight Hashrate Pushes Standard Adoption
The Working Group was founded in 2022 by Braiins and Spiral, Block Inc.'s Bitcoin technology arm. It has operated as an independent open-source community for over four years. With the addition of large-scale operators like Antpool and F2pool, the group is now entering "a new phase of accelerated development and deployment."
Andy Zhou, CEO of Antpool, said his firm is "proud to support the broader adoption of Stratum V2," adding that alignment around an open, interoperable standard allows the industry to collaborate on efficiency, security, and decentralization. Kenway Wang, CTO of Spiderpool, noted that the protocol supports miner-created blocks, which is especially useful for operators in bandwidth-constrained environments.
Braiins Pool and DMND are already running Stratum V2 in production. DMND launched in 2025 as one of the first pools to offer fully miner-selected blocks. Blitzpool runs it for individual miners, and the Stratum V2 Reference Implementation community pool continues testing. Foundry, Luxor, and Antpool had previously committed to testing or prepared infrastructure before this announcement.
The seven new members represent tens of exahashes per second of combined hashrate. Currently, about five pools control roughly 70% of global hashrate and thus the majority of block content. Stratum V2's adoption is expected to gradually reduce this centralization.
Low Barriers for Individual Miners
For individual Bitcoin miners, the practical change depends on when these pools enable V2 access for users. Translation proxies already allow Stratum V1 firmware to connect to V2 pools without requiring hardware or firmware upgrades, lowering the barrier to entry significantly. Miners can immediately benefit from lower latency, enhanced privacy, and potential profitability gains.
The collective action of these seven mining giants is widely viewed as the most significant protocol upgrade signal since the inception of Bitcoin mining. As more pools join, Stratum V2 is poised to become the new industry standard, driving the mining ecosystem toward greater decentralization, efficiency, and miner autonomy.