Bitcoin’s second-busiest block ever held 11,255 transactions, but paid miners just 0.0024 BTC in fees

Bitcoin block 974,961, mined by AntPool at 18:24 UTC on Saturday 7 November, carried 11,255 transactions, the second-highest count ever packed into a single block, according to mempool.space developer mononaut. The block was 99.85% full by weight. Yet all those transactions together paid 240,533 satoshis in fees, or 0.0024 BTC, according to the block’s data on mempool.space.

The count looks like a crowd of users rushing to get on-chain. The fee total says something else. Most of the space went to near-identical 80-byte transactions that each pay a single satoshi, mint one unit of UNCOMMON•GOODS, the first Runes token, and hand a pay-to-anchor output on to the next transaction in a chain. Bitcoin.com counted 10,585 transactions in the block paying less than 1 sat/vB, taking 87.7% of its space.

Transaction counts and fee pressure are two different measures, and this block pulls them about as far apart as they go. It also carried thousands of transactions priced below the relay floor of a default Bitcoin Core node, and no source has yet said how they reached the smart contract holding reserves of two or more tokens, supplied by users, that a decentralized exchange uses to execute trades automatically at a price set by a formula.">pool.

Block 974,961 in numbers: 11,255 transactions in a 99.85% full block

The figures below come from the mempool.space API, queried by Coindaro on Monday 9 November around 08:15 UTC. The block weighs 3,993,844 weight units against a limit of 4,000,000, which is where the 99.85% comes from. It holds 11,793 inputs and 23,122 outputs, and its transactions average 98 bytes each.

The blocks around it were far less crowded by count. Block 974,960, mined just before it, also by AntPool, held 4,846 transactions and paid 0.0154 BTC in fees; block 974,956 held 5,165. In the 14 blocks before it, counts ran from 1,955 to 5,165. All of them weighed about the same, just under 4 million weight units. Block 974,961 was not bigger. Its transactions were smaller, and at 1.10 MB it was in fact lighter in raw bytes than any of those 14, which ranged from 1.43 MB to 1.91 MB.

Source: mempool.space API for both blocks, read 9 November 2026.

Second highest ever, 984 transactions short of the 2015 record

Mononaut, a developer at mempool.space, flagged the block on X on 7 November. “New #2 record: 11,255. We’re rapidly closing in on the all-time high of 12,239 transactions from block 367853,” he wrote, as quoted by Bitcoin.com News, which wrote the block up on 8 November. Phemex carried the same ranking.

It was the second such mark in a week. On 4 November, mononaut had flagged block 974,557, also mined by AntPool, with 10,573 transactions as “the second highest figure of all time”, according to the same Bitcoin.com article. Three days later, block 974,961 passed it by 682.

Coindaro checked the record holder. Block 367,853, mined by F2Pool at 01:06 UTC on 1 August 2015, does hold 12,239 transactions in mempool.space data, so the 2026 block falls 984 short. The “second highest” ranking is mononaut’s, repeated by Bitcoin.com and Phemex.

The 2015 block came from a different era. It predates SegWit, when the limit was a plain 1 MB, and the block filled 999,956 bytes of it. According to Bitcoin.com, 442 of its transactions paid 32 sat/vB or more and used 26.8% of the space, while 11,796 paid under 1 sat/vB and took 73.1%. Bitcoin.com adds that F2Pool mined block 367,851 the same day with 9,647 transactions.

What filled the block: Runes mints chained through pay-to-anchor outputs

Coindaro read samples of the block’s transaction list through the mempool.space API, from the top of the block to its last 30 entries. The block opens with roughly 230 ordinary fee-paying transactions, sorted from 18 sat/vB down to about 1 sat/vB; 13 of them paid 5 sat/vB or more. A short band paying 0.1 to 0.9 sat/vB follows. After that comes a long run of transactions that look almost identical, almost to the end; the block closes with about 30 smaller runestone transactions at 0.12 sat/vB. One example, d2b927b9…b2b9, is 80 bytes long, weighs 320 weight units (80 vB) and pays a fee of exactly 1 satoshi.

Its single input spends a pay-to-anchor output worth 255 satoshis. It creates two outputs. The first is a new pay-to-anchor output worth 254 satoshis. The second is an OP_RETURN output that starts with OP_13, the marker the Runes protocol uses for its messages, called runestones. The message itself is four bytes: 14 01 14 00. Coindaro read them against the published Runes specification, which encodes a runestone as pairs of numbers: tag 20 (0x14) is “Mint”, given twice, with the values 1 and 0. That spells a request to mint rune ID 1:0. In the source code of ord, the reference Runes software, 1:0 is the ID of UNCOMMON•GOODS, a rune built into the protocol with an open mint of one unit per transaction. This decoding is Coindaro’s own, not a statement from the minters, and it agrees with Bitcoin.com’s identification of the token.

The next transaction spends that 254-satoshi output and leaves 253, the one after leaves 252, and so on. Each link pays one satoshi as its fee and asks for one more mint. In the stretches Coindaro read, the chains run about 25 transactions. A wallet transaction of about 220 bytes opens each one with a 263-satoshi anchor, 23 links of 80 bytes walk it down to 240 satoshis, and a closing transaction spends the last anchor together with a wallet input, so the remaining 240 satoshis go to the miner as fee. Every step, opener and closer included, carries the same runestone.

Pay-to-anchor, or P2A, became a standard output type in Bitcoin Core through pull request #30352, covered by Bitcoin Optech in August 2024, and shipped in Bitcoin Core 28.0 on 2 October 2024. Its script, OP_1 followed by the two bytes 4e73, holds no key: anyone can spend it, with no signature. It was designed so that a second transaction can attach a fee to a first one, mainly for Lightning-style contracts. Here, the lack of a signature is what keeps each link down to 80 bytes. Under the Runes rules, runes that no instruction directs go to the first output that is not an OP_RETURN, which in each link is the new anchor; on Coindaro’s reading, the minted units ride down the chain until the closing transaction moves them to the wallet’s own output.

Runes itself went live at the April 2024 halving, explained in our guide to the bitcoin halving and block reward. UNCOMMON•GOODS was the protocol’s first token. In ord’s code, its mint is open to anyone from block 840,000, the 2024 halving, to block 1,050,000, the next one, at one unit per mint and with no practical cap.

How many of the 11,255 transactions follow this pattern exactly is not published. Bitcoin.com gives 10,585 transactions under 1 sat/vB, about 94% of the count. A rough check fits Bitcoin.com’s figure: 10,585 transactions of 80 vB would fill 846,800 vB, or 84.7% of the block’s 1,000,000 vB, close to Bitcoin.com’s 87.7% once the larger openers, closers and the 0.1 to 0.9 sat/vB band are added.

0.0024 BTC in fees against a 3.125 BTC subsidy

AntPool collected 3.12740533 BTC for the block: the 3.125 BTC subsidy plus 0.00240533 BTC in fees. The fees were about 0.077% of the subsidy. Spread over the block’s roughly 998,461 virtual bytes, they work out to about 0.24 sat/vB on average, a figure pulled up by the 230 or so ordinary payments at the top of the block.

mempool.space shows a median fee rate of 0 sat/vB for the block, a rounding of the 1-satoshi fee over 80 vB, which is 0.0125 sat/vB. Counted as a whole, one 25-transaction chain pays about 266 satoshis for roughly 2,150 vB, about 0.12 sat/vB (Coindaro’s arithmetic from the sampled chain). At the old 1 sat/vB floor, the 80-byte links alone would have cost 80 satoshis each instead of one. The block just before, 974,960, paid AntPool about six times as much in fees with less than half the transactions.

For miners, the subsidy is still almost all the income from a block like this one, a point that matters as mining difficulty is set to fall on 13 November. The block also shows the trade a pool makes when it accepts such transactions: the space they take could have gone to payments at 1 sat/vB or more, but only if enough of those were waiting.

How transactions under 0.1 sat/vB reached a miner: Coindaro’s reading

For years, Bitcoin Core nodes refused by default to relay transactions paying under 1 sat/vB. Bitcoin Core 30.0, released on 10 October 2025, cut the default minimum relay fee rate and the incremental relay fee rate to 0.1 sat/vB. Its release notes warn that transactions created at lower rates “are not guaranteed to propagate or confirm” unless the lower defaults are widely adopted. Wallet fee rates did not change. The same release set the default minimum fee rate for transactions a miner’s node puts in a block template, -blockmintxfee, at 0.001 sat/vB. The history of the floor is tracked by Bitcoin Optech.

The mint transactions in block 974,961 pay 0.0125 sat/vB. That is eight times below even Core 30’s new default, and 80 times below the 1 sat/vB floor that older nodes still apply. A node running either set of defaults would not accept them one by one into its mempool or pass them on, and Core’s package relay, per the 30.0 notes, covers one parent with one child, not chains of 25. The chain as a whole, at about 0.12 sat/vB, would clear the 0.1 floor, but each 80-byte link on its own does not.

Our reading, which no source has confirmed: these transactions most likely did not travel through the public relay network with default settings. They probably reached AntPool by another route, either submitted to the pool directly or through nodes configured with a lower floor. Once in a pool’s mempool, a fee rate of 0.0125 sat/vB sits above Core 30’s default block-template floor of 0.001 sat/vB, so nothing in the default template rules would keep them out. Nothing shows that Core 30’s lower relay default played a part in this block. AntPool has not commented, and Coindaro found no statement from the people behind the mints.

What the block says about fees for ordinary users, and what it does not

Normal payments in the same block paid from about 1 to 18 sat/vB, and the block itself gives no sign that they were pushed out or overcharged. The mints took space that was, at that moment, not in demand at higher rates. A full block is not proof of congestion when most of it pays almost nothing.

Nor is the transaction count a measure of adoption or of price demand. The same chain of 80-byte mints could be produced by a single party. Bitcoin.com lists 23 April 2024 as the busiest day on record with 927,010 transactions, followed by 23 October 2026 with 913,196; those are daily totals, a different measure from a single block.

The same article puts November well below that pace: about 534,200 transactions a day over the month’s first seven days, roughly 25% under October’s average of 710,400, with 591,830 on 7 November itself.

Anyone can look at the block the same way. Open it on an explorer, sort by fee rate and compare the first and last transactions; our guide to reading a block explorer walks through the fields, and our explainer on the mempool and bitcoin fees shows how fee rates in sat/vB decide which transactions a miner picks. The Bitcoin (BTC) page carries the network’s live data.

Open questions: who paid for the mints, and whether the 2015 record falls

Several things are still unknown. Nobody has said who built and paid for the chains of mints, or why they ended up in an AntPool block rather than another pool’s. The exact number of Runes and P2A transactions in the block has not been published. And mononaut’s words, “rapidly closing in”, leave open whether a future block will pass 12,239.

The UNCOMMON•GOODS mint stays open until block 1,050,000, about 75,000 blocks away, so nothing in the token’s own rules stops more chains like these. The next fixed date for miners is the difficulty adjustment expected on 13 November.