Most of the blocks on the Bitcoin chain are already carrying headers from other networks. Nathan Hatzfeld put the figure at roughly ninety percent in data he described as a couple of years old, and said that today the number is probably close to one hundred percent. His point was that the miners producing those blocks are, for the most part, not the ones collecting the reward for it.
At Mining Disrupt Miami 2022, held July 26–28, 2022, Hatzfeld, Business Development at Syscoin, made the case for merged mining, a feature of Bitcoin he called overlooked. He spoke for Syscoin and its partner team, JAX.NETWORK, and his aim was plain: raise awareness among miners and get them mining the side chains that are pegged to Bitcoin's hashrate.
The idea itself is old. Hatzfeld traced it to a 2010 discussion by Satoshi, and said Namecoin later turned it into a standard. By his count there are now somewhere between ten and twenty coins considered merge mined. The mechanism lets a miner take the hash it is already computing for a Bitcoin block and apply that same work to several other chains at the same time, so each of those chains can draw on Bitcoin's hashrate for its own algorithm.
Merged mining is an overlooked feature set of Bitcoin that allows miners to take a hash that is solving for the Bitcoin block and apply it to multiple chains concurrently.
Nathan Hatzfeld · 0:00
Hatzfeld framed merged mining as a potential answer to what he called the blockchain trilemma, the balancing act between scalability, decentralization and security. He also described it as an elegant fit for the current debate over modular design, since the security layer is shared rather than rebuilt chain by chain.
The urgency in his talk came from what he called Bitcoin's longevity problem. The subsidy falls at every halving, roughly every four years, and on-chain fees are capped by a block weight that limits how many transactions fit in a block. That limit, he said, settled concerns about decentralization at the time but created problems down the road that still have to be addressed. Eight years out, he said, Bitcoin production drops sharply, and for miner revenue to hold up the price would have to climb exponentially, perhaps past a million dollars. He was clear there is no guarantee of that.
So today we're probably looking at about 100% of blocks that contain headers from side chains pegged to Bitcoin.
Nathan Hatzfeld · 1:31
Merged mining, in his telling, is a third source of revenue that can keep Bitcoin's security budget high without depending on that price outcome. His example was Litecoin and Doge: mining Doge, he said, is roughly two to three times as profitable as mining Litecoin on its own. Under proof of work, a network is exactly as secure as it is hard to attack, and more revenue flowing on chain makes any attack costlier. That is why he called merged mining a key piece of Bitcoin infrastructure going forward.
And so merged mining offers a potential third sourcer revenue to keep the security revenue of Bitcoin high.
Nathan Hatzfeld · 1:56
The pitch to miners was about cost as much as security. Hatzfeld said there is no extra cost, no overhead, no downtime risk, and no added complexity to the mining operation. Setup, he said, takes under twelve hours and often about an hour plus the time to sync the blockchain, and several coins can be mined together. He also argued it improves the ESG picture for Bitcoin, because more value comes out of each kilowatt put into the mining system, and the added mining is carbon neutral.
It is money left on the table.
Nathan Hatzfeld · 2:48
The gap, he said, is awareness. Merged mining is best known among developers. Some of the miners he has spoken with were aware of it, but most were not. Most pools appear to merge mine to some degree, yet they are not sharing that information with the miners who connect to them, and in his description the pools have been collecting the coins on the back end rather than passing them along. His ask was for miners to go to their pools and start asking to merge mine these tokens.
So part of raising awareness about this is getting miners to reach out to these pools and start asking to merge mine these tokens.
Nathan Hatzfeld · 5:05
That is where the Global Merge Mine Alliance comes in. Hatzfeld described himself as a founder of the alliance, co-founding it with JAX.NETWORK. The plan is a network that aggregates the merge-mined tokens in one place where people can meet, share research and knowledge, and build out the ecosystem around Bitcoin. He named Rootstock as one of the better-known chains already in this category, and said there are many more.
Syscoin, he explained, is essentially Ethereum running on SHA-256: byte-for-byte EVM compatibility brought to Bitcoin, with a design aimed at rollups. JAX.NETWORK, the partner organization, is a layer-one chain that lets users burn Bitcoin to mint a stablecoin. Hatzfeld contrasted it with the algorithmic, over-collateralized and under-collateralized designs the market is still working through, and said JAX.NETWORK ties the stablecoin mint rate to the energy and hash input behind the burn, which is how it controls inflation without big trade-offs.
He also set the talk against Ethereum's move to proof of stake. After that switch, he said, there will not be a big proof-of-work market left. Proof of work tends to be winner-takes-all, and a scattering of small proof-of-work chains raises systemic risk for each of them. Merged mining lets proof-of-work projects build inside chains pegged to Bitcoin's hashrate instead of standing alone.
This is free. We're leaving this on the table. We're not exploring this.
Nathan Hatzfeld · 8:03
Hatzfeld closed by inviting miners to the Syscoin and JAX.NETWORK booth, saying there was a lot of potential and a lot to talk about. The session was recorded when Bitcoin traded near $21,268. As of October 16, 2026, it is at $82,165. The question he raised, where miner revenue comes from once the subsidy thins, is the one he asked in Miami.