mempool flooded with an abnormal number of large transactions

The Bitcoin blockchain mempool (BTC) has reached its highest levels since January of last year: data from the Blockchain.com website reveal it.

On November 15, the size of the Bitcoin mempool exceeded 90 megabytes (MB), a value that had not been recorded since January 2018. The mempool contains all the unconfirmed transactions that are waiting to be validated by the miners.

Size of the mempool (in bytes) in the last year. Source: Blockchain.com

It would seem to be an anomaly

In most cases, the bigger the mempool, the more transactions are waiting to be confirmed by the miners. However, in this case, the situation is quite different: the number of unconfirmed transactions present in the Bitcoin mempool has just over 20,000.

That number was higher – even if only by a couple of hundred transactions – two days ago, while the size of the mempool was "just" 12.6 MB. All these data seem to indicate that over the past weekend, the average transaction size was significantly larger than usual.

Larger transactions usually include many inputs or outputs, or simply store data on the blockchain. Alex Saunders, CEO and founder of the Australian news site NuggetsNewsAU, wrote about Twitter that the phenomenon could be linked to the activities of the Binance cryptocurrency exchange.

Saunders claims that the mempool was filled by Binance by moving small amounts of Bitcoin or Tether (USDT) based on Omni from many addresses, and with the lowest possible commissions, which causes transactions to remain in the mempool for even longer .

At the end of 2017, the Bitcoin mempool reached 120MB, and in the same period a transaction could cost as much as $ 16. At the time, analyst and researcher Nic Carter claimed that the suspicious behavior of the mempool was due to the huge amount of transactions that were flooding the network, often sent – even in this case – by paying the lowest possible rates.