This week, seven of the largest Bitcoin mining companies officially joined the Stratum V2 working group, marking the industry’s clearest transition yet to miner-controlled transaction selection.
Important points:
- Antpool, F2pool, Foundry, and four others joined the Stratum V2 working group on May 7, 2026.
- Stratum V2 offers miners up to 7.4% higher profitability through reduced latency and improved fee capture.
- Brains and Spiral will establish a working group in 2022 and enter a new implementation phase in 2026.
7 Bitcoin Mining Pools Return to Stratum V2 as Miners Push Block Template Control
Antpool, F2pool, Foundry, Spiderpool, Block Inc., MARA Foundation, and DMND are currently participating in efforts to advance open mining protocol standards. This announcement was published by Pavlenex on the official website of the Stratum V2 Working Group.
Stratum V2 replaces Stratum V1, a push-based protocol released by Marek “Slush” Palatinus in 2012. Although Stratum V1 became the industry default, it was never designed as an official standard. V1 gave pools full control over transaction selection, executed in cleartext, and exposed miners to hashrate hijacking and surveillance.
The new protocol addresses these issues. It uses end-to-end authenticated encryption, reduces bandwidth usage by about 60% on the pool side and 70% on the miners, and introduces a job declaration subprotocol that allows miners to build their own block templates instead of accepting pool allocations.
According to the official announcement, “By keeping Stratum V2 as a vendor-neutral public specification, we remove compatibility barriers and allow the ecosystem to focus on what matters most: increasing efficiency, privacy, security, and miner autonomy, which ultimately leads to increased profitability.”
Real-world testing by Brains shows that miners can earn up to 7.4% higher profitability when running V2 natively due to faster template delivery, lower latency, and improved pricing options.
Antpool CEO Andy Zhou said the company is “proud to support the widespread adoption of Stratum V2,” adding that aligning around open and interoperable standards will enable the industry to collaborate on efficiency, security, and decentralization. Spiderpool CTO Kenway Wang said the protocol supports miner-built templates, making it especially useful for operators in bandwidth-constrained environments.
Brains Pool and DMND are already running Stratum V2 in production. DMND was launched in 2025 as one of the first pools to provide complete templates for miners to choose from. Blitzpool is doing this for solo miners, and the Stratum V2 reference implementation community pool continues testing.
The working group was established in 2022 by Brains and Spiral, Block’s Bitcoin technology arm. The group has been operating as an independent open source community for more than four years and is now entering “a new phase of accelerated development and deployment” with the addition of larger operators.
Foundry, Luxor, and Antpool each had pre-testing commitments or infrastructure in place prior to this announcement. The seven new additions equate to tens of exahashes per second in total hashrate. This number is important because around five pools currently control about 70% of the world’s hashing power and therefore most block content.
For individual Bitcoin miners, the actual transition will depend on when these pools enable V2 access to their users. Translation proxies lower the barrier to adoption by allowing Stratum V1 firmware to connect to V2 pools without requiring any hardware or firmware upgrades.
