Bitcoin's mining concentration just showed up in a rare 2-block reorg

A rare 2-block chain reorganization occurred on the Bitcoin network at block height 941,881, serving as a clear on-chain signal of increasing mining concentration. The event involved Foundry USA, the largest mining pool, producing a sequence of blocks that ultimately orphaned two valid blocks mined by AntPool and ViaBTC. This happens when two miners find blocks nearly simultaneously, briefly splitting the network until the chain with the most cumulative proof of work wins. Foundry's chain quickly grew longer, causing the network to adopt it and discard the blocks from the competing pools. This event coincided with a recent 7.76% drop in Bitcoin mining difficulty, as lower prices force smaller miners to exit, concentrating the remaining hashrate into fewer pools like Foundry. While a 2-block reorg does not threaten Bitcoin's security, it increases the probability of future simultaneous block finds by dominant pools.

(Source：CoinDesk)