The largest ever bitcoin block, measured by byte size, has been mined — and it consists entirely of a Bitcoin Ordinals inscription. 

The block was mined by bitcoin mining firm Marathon Digital’s Slipstream, a direct transaction submission service on bitcoin made possible by the company’s proprietary mining pool MARA, and OrdinalsBot, a service that simplifies the process of inscribing Ordinals.

“Note that these aren’t the largest ever block and transaction by weight, those titles are firmly held by F2Pool,” said bitcoin developer “mononaut” on X. 

The block measured 3,990.36 kilobytes and was mined on March 2, containing a Runestone inscription. Runestones is a Bitcoin Ordinals project led by pseudonymous Ordinals collector LeonidasNFT, who has long been an advocate for Casey Rodarmor’s creation — the Bitcoin Ordinals protocol.

Bitcoin Ordinals are similar to Ethereum-based non-fungible tokens (NFTs) and allow data, including JPEGs and text to be inscribed on the Bitcoin blockchain. In September, Rodarmor proposed creating a new protocol called Runes, which would be a UTXO-based alternative to the BRC-20 token standard.

Runestones was likely created in anticipation of Runes, a core protocol created by Rodarmor that is still to launch. Runestones are set to be airdropped to users that hold at least three inscriptions in their wallet, excluding file types that start with “text/plain” or “application/json.” Holders of cursed inscriptions, or those inscriptions that the tool that indexed ordinals originally overlooked, are also included.

“The top blockchain in the world should have the top meme coin in the world,” said LeonidasNFT explaining the logic behind the Runestone project on X.

“The top meme coin in the world should be distributed via a massive free airdrop with no team allocation to the most based community,” he said.

Around 112,000 Runestones are expected to be airdropped to eligible wallets, and at the time of writing, these inscriptions were trading on OTC exchange WhalesMarket between a price range of $839 and $4,300.

This article has been updated to clarify the date/time of the block creation.