Marathon Fusion says it turned mercury into “real, stable gold,” beating CERN’s record by a factor of 10. The San Francisco startup announced the result on X on October 21.
The post set off a familiar worry among traders. If a reactor can make gold, can the metal still lean on its scarcity?
How Much Gold Could a Fusion Reactor Really Make?
Crypto Bitlord wrote on X that gold may not be so rare after all. Multicoin Capital founder and CIO Tushar Jain took the concern further, comparing it to what lab-grown stones did to diamond prices.
But is fusion-made gold really a reason to worry about gold prices right now?
The demonstration itself offers little to measure. Marathon’s thread did not say how much gold the test produced or which CERN record it beat. It also shared no experimental data, and the rest of the thread focused on medical isotopes rather than gold.
For scale, CERN’s ALICE team measured about 29 picograms of gold from the LHC’s 2015 to 2018 run. Those gold nuclei came from 4 experiments and broke apart within a fraction of a second.
Marathon’s own research gives a better sense of what a full-size plant could produce. Its 2025 paper modeled about 2 tonnes of gold per gigawatt of thermal power each year.
By comparison, global mines produced 3,672 tonnes of gold in 2025, according to the World Gold Council. Another 222,600 tonnes of mined gold already exist above-groundas of Q2 2026.
Even the paper’s 2-tonne figure assumes plants far larger than anything Marathon runs today. Its website lists its current reactor at 1 kilowatt of fusion power, a millionth of a gigawatt.
The gold would not reach buyers right away either. Marathon’s paper says freshly made gold would carry some radioactive isotopes.
Depending on the safety standard, it would need 7 to 17 years of storage before sale. The authors add that purifying the mercury feedstock could shorten that wait.
Fusion-made gold therefore remains years away from any market. Gold’s price, however, had been sliding for months before Marathon’s post.
How Gold’s Price Has Held Up Through a Bruising 2026
Market data shows gold trading 5.56% below its January 1 level, with the metal down another 1.2% today. Gold had climbed roughly 25% above its January 1 level in late January before reversing.
Market account Bull Theory reported that gold erased about $406 billion in value. Silver dropped 3% over the same window, lifting combined losses above $500 billion.
Nonetheless, some analysts see the decline nearing its end. Founder of IntoTheCryptoverse Benjamin Cowen said he believes gold is in the late stages of its bear market. He added that the metal could still struggle a while longer.
For now, the bigger test for gold holders sits in that chart rather than in Marathon’s lab. The coming weeks will reveal whether the metal can recover its 2026 losses or whether the selling has further to run.
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