75% of Bitcoin's Hashrate Just Backed Stratum V2 — Block Construction Returns to Miners!

Seven of the world's largest bitcoin mining pools — Foundry, AntPool, F2Pool, SpiderPool, MARA Pool, Block Inc, and DMND — have joined the Stratum V2 working group, collectively representing nearly 75% of global hashrate. Foundry alone controls 34.2%, AntPool 14.2%, F2Pool 11.3%, and SpiderPool 10.5%, per Hashrate Index data.

The structural shift that matters: Stratum V2 moves block template construction from pool operators back to individual miners. Under the current Stratum V1 standard, whoever runs the pool decides which transactions go into each block — a concentration of power the Bitcoin community has flagged as the real systemic risk, distinct from hashrate concentration itself.

The protocol has existed since 2022, when Braiins and Spiral co-founded the working group, but was treated as a niche side project until now. Foundry and AntPool's participation gives it genuine reach,…