Five of the largest Bitcoin mining pools — Foundry, AntPool, F2Pool, SpiderPool, and MARA Pool — have joined the Stratum V2 working group, the organization behind the open standard protocol. They're among seven pools that together represent roughly 75% of the global Bitcoin hashrate. The move signals a shift toward decentralizing block construction decisions back to individual miners rather than pool operators.
What Stratum V2 changes
Stratum V2 is an open standard protocol designed to change how mining pools and individual miners interact. The key difference from the older Stratum V1: it returns block construction decisions to the individual miners. Under V1, the pool operator typically decides which transactions go into a block. With V2, miners get to choose the transaction set themselves, reducing the pool's control over the block template. That's a big deal for people who want more autonomy in what they mine.
Who's in the group
The working group now includes at least these five named pools: Foundry USA, AntPool, F2Pool, SpiderPool, and MARA Pool. Two other pools have also joined but weren't named in the announcement. Combined, the seven pools control about three-quarters of all Bitcoin mining power globally. That gives the group serious weight — it's not a fringe standard anymore.
With 75% of the network's hashrate backing it, Stratum V2 has a real shot at becoming the default way miners talk to pools. That would mean a meaningful step away from the centralization that critics have warned about for years. Pool operators lose some power; individual miners gain some back. The shift won't happen overnight — pools have to update their software, and miners need compatible hardware or firmware — but the buy-in from the biggest pools removes a major hurdle.
Whether smaller pools — representing the remaining quarter of hashrate — will adopt the standard remains an open question. But with the largest players already on board, the pressure is on.
