Uploaded April 2023 | Updated September 2026, 1 hour ago

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This Q&A is an excerpt from an answer Andreas gave during the March 2023 Q&A session for patrons. The question was related to the large reorg that happened during Bitcoin's early days and specifically what happened to the transactions that weren't actually confirmed. During the answer, it became clear that people needed clarification as to what "the" mem pool actually is and what it's not. Hint: there is no "the" mem pool. If you want to join the Q&A sessions, simply become a patron at patreon.com/aantonop

Video description: Welcome back to our deep dive into the world of bitcoin. Today, we're spotlighting 'mempools', an often overlooked but crucial part of every blockchain node. Mempools are, in essence, a waiting area for unconfirmed transactions. They're used by both miners, who are looking for transactions to include in the next block, and wallets that need to keep tabs on unconfirmed payments and pending transactions.

And here's where it gets interesting - even though each node has its own mempool, they're almost identical, with over 99.99% of the transactions being the same across different mempools. This high degree of synchronicity is what makes the blockchain system work. Even in the case of a rollback, where blocks are discarded, nodes can quickly repopulate their mempools either from their own backlog or from other nodes, ensuring that no transaction gets lost in the shuffle.

So if you're into #BlockchainTechnology, #CryptocurrencyMining, or just want to know #HowBitcoinWorks, keep watching our videos to get the lowdown on these important topics. Remember to subscribe and hit the bell icon to stay updated on our latest content! #BitcoinExplained #Mempools #Decentralization

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