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

A 2-block reorg at height 941,881 saw Foundry's chain overwrite blocks from AntPool and ViaBTC, coming days after mining difficulty dropped nearly 8%. What to know : Foundry USA, Bitcoin's largest mining pool, briefly produced seven consecutive blocks on Monday, triggering a rare two-block chain reorganization that orphaned valid blocks from AntPool and ViaBTC. The incident, which the network resolved as designed by favoring the chain with the most cumulative proof of work, underscores how shrinking industry margins are concentrating hashrate into fewer, larger mining pools. While a two-block reorg does not threaten Bitcoin's overall security, growing hashrate concentration increases the odds that a single pool will mine multiple blocks in a row and create short-lived competing chains when blocks are found nearly simultaneously.(Coindesk)