Bitcoin Mining Pool Giants Foundry, Antpool and F2pool Signal Stratum V2 Shift

Seven of the largest names in bitcoin mining formally joined the Stratum V2 Working Group this week, signaling the clearest industry shift yet toward miner-controlled transaction selection.

Key Takeaways:

7 Bitcoin Mining Pools Back Stratum V2 as Miners Push for Block Template Control

Antpool, F2pool, Foundry, Spiderpool, Block Inc., MARA Foundation, and DMND are now part of the effort to advance the open mining protocol standard. The announcement was published by Pavlenex on the Stratum V2 Working Group’s official site.

Stratum V2 replaces Stratum V1, a push-based protocol released in 2012 by Marek “Slush” Palatinus that became the industry default but was never designed as a formal standard. V1 left pools in full control of transaction selection, ran in plaintext, and exposed miners to hashrate hijacking and surveillance.

The newer protocol addresses those problems. It uses end-to-end authenticated encryption, cuts bandwidth use by roughly 60% on the pool side and 70% for miners, and introduces a Job Declaration sub-protocol that lets miners build their own block templates instead of accepting what pools assign.

According to the official announcement, “By maintaining Stratum V2 as a public, vendor-neutral specification, we remove compatibility barriers and allow the ecosystem to focus on what matters most: improving efficiency, privacy, security, and miner autonomy, ultimately leading to increased profitability.”

Real-world tests from Braiins show miners can capture up to 7.4% higher profitability through faster template delivery, lower latency, and improved fee selection when running V2 natively.

Antpool CEO Andy Zhou said the company is “proud to support the broader adoption of Stratum V2,” adding that aligning around an open, interoperable standard lets the industry collaborate on efficiency, security, and decentralization. Spiderpool CTO Kenway Wang noted the protocol supports miner-constructed templates, which are 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 full miner-selected templates. Blitzpool runs it for solo miners, and the Stratum V2 Reference Implementation community pool continues testing.

The Working Group was founded in 2022 by Braiins and Spiral, Block’s Bitcoin technology arm. The group has operated for more than four years as an independent open-source community and is now entering “a new phase of accelerated development and deployment” with the addition of large-scale operators.

Foundry, Luxor, and Antpool had each made prior testing commitments or prepared infrastructure before this announcement. The seven new additions represent tens of exahashes per second of combined hashrate, a figure that matters because roughly five pools currently control about 70% of global hashpower and therefore most block content.

For individual bitcoin miners, the practical shift 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, which reduces the barrier to adoption.