Bitcoin Blockchain Undergoes Two-Block Reorg

Bitcoin's blockchain underwent a rare two-block reorganization on March 23, 2026, when competing mining pools produced parallel versions of the ledger, ultimately resolved in favor of the chain extended by Foundry USA, the network's largest mining pool.

The event unfolded around block heights 941,880 to 941,886. At height 941,881, AntPool mined a valid block at 15:49:35 UTC, followed just 12 seconds later by Foundry USA mining its own version at 15:49:47 UTC. This created an initial split, with some network nodes accepting one block and others the other. The competition intensified at height 941,882, as ViaBTC extended the AntPool branch with another block, while Foundry USA added to its own branch. For a brief period, the network operated with two competing chains, each two blocks long.

Foundry USA then mined blocks 941,883 through 941,886, securing six consecutive blocks in total and establishing a longer chain with greater cumulative proof-of-work. Bitcoin's consensus rules automatically favored this branch as the canonical ledger, discarding the AntPool and ViaBTC blocks as orphaned or stale. These blocks, though valid, received no rewards for their miners, and the...