Seven major Bitcoin mining pools join Stratum V2 working group

Seven of the biggest names in Bitcoin mining just agreed to sit at the same table. AntPool, Block Inc., F2Pool, Foundry, MARA Foundation, SpiderPool, and DMND have all joined the Stratum V2 working group, a collaborative effort to overhaul the communication protocol that mining pools use to coordinate with individual miners.

What Stratum V2 actually changes

Since 2012, Bitcoin mining pools have communicated with their miners using a protocol called Stratum V1. The problem is that V1 was designed in a different era, and it shows.

Stratum V1 sends data in plaintext, meaning it’s vulnerable to eavesdropping and manipulation. More importantly, V1 gives mining pool operators exclusive control over block template construction. In English: the pool decides which transactions go into a block, not the individual miners contributing hashpower.

Stratum V2 flips several of those dynamics. The upgraded protocol introduces end-to-end encryption, more efficient fleet management for large-scale operations, and, critically, the option for individual miners to build their own block templates.

The working group itself was founded in 2022 by Braiins and Spiral, Block Inc.’s Bitcoin development arm, with the goal of creating a vendor-neutral open standard. The addition of seven major pools transforms it from a niche initiative into something resembling an industry consensus effort.

The numbers behind the upgrade

Beyond the governance implications, there’s a straightforward economic case for Stratum V2. The protocol’s reduced latency and improved data handling could translate to up to 7.4% higher profitability for miners, according to the Stratum V2 project.

The pools joining the working group represent substantial hashrate. AntPool and F2Pool alone account for roughly 25-35% of global Bitcoin mining capacity. Add Foundry, which has consistently been one of the largest pools by hashrate, plus MARA Foundation (the mining arm associated with Marathon Digital), and you’re looking at a working group that represents a meaningful share of Bitcoin’s total computational power.

Why this matters for Bitcoin’s architecture

Stratum V2 doesn’t eliminate mining pools. It restructures the relationship between pools and their members. Miners can still benefit from pooled resources while retaining the ability to construct their own blocks. The pool handles reward distribution. The miner handles transaction selection.

The fact that Block Inc. is involved is notable for a separate reason. Block’s Spiral division was one of the original co-founders of the working group. Block also manufactures Bitcoin mining hardware, giving it a direct path to embed Stratum V2 support at the chip level.

What this means for investors

For investors in publicly traded mining companies like Marathon Digital (whose MARA Foundation joined the working group), the Stratum V2 transition represents a potential efficiency gain. A 7.4% improvement in profitability, if realized, would meaningfully impact margins in a business where the difference between profit and loss often comes down to a few percentage points on electricity costs and operational efficiency.