The Bitcoin blockchain has recently undergone a somewhat uncommon event known as a two-block reorganization (often referred to as a “reorg”).
While the term “reorganization” might raise concerns for those unfamiliar with blockchain technology, it’s important to clarify that this occurrence was neither an attack nor a malfunction. The decentralized consensus mechanism of Bitcoin is operating precisely as intended.
We just had a rare-ish two block fork/reorg between Foundry and AntPool+ViaBTC. Foundry mined six blocks in a row. https://t.co/qpj7eLlh0U pic.twitter.com/Jd5m1LX036
— b10c (@0xB10C) March 23, 2026
Insights from Bitcoin researcher b10c reveal that the mining pool Foundry USA triumphed in an intense multi-block competition against rivals AntPool and ViaBTC.
The Competition at Block Height 941880
Miners are in constant competition to validate transactions by solving intricate cryptographic challenges.
A temporary split occurred within the network at block height 941880, leading to two competing chains. AntPool successfully mined block 941881, followed shortly by ViaBTC which mined block 941882 on the same chain. Meanwhile, Foundry USA also created its own version of block 941881 and subsequently found its version of block 941882.
This situation resulted in two valid chains existing simultaneously with equal lengths until it was resolved when Foundry USA continued its winning streak by mining blocks 941883, 941884, and finally, block 941885.
The blocks produced by AntPool and ViaBTC were ultimately discarded as they became what are referred to as “stale” or “orphaned” blocks. In totality, Foundry USA achieved an impressive feat by mining seven consecutive blocks ranging from heights of 941879 through to 941885.
While single-block reorganizations occur from time to time within the network’s operations, instances involving two-block reorganizations are considerably less frequent. This signifies that the temporary stalemate between both chains lasted for an entire additional cycle of blocks.