Marathon Fusion gold yield matches its simulation by...?

About this market

On October 21, 2026, Marathon Fusion announced that it had "demonstrated high-rate alchemy," turning mercury into stable gold using fusion neutrons and "beating CERN's record by a factor of 10." (see: https://startupfortune.com/marathon-fusion-says-it-turned-mercury-into-gold-no-proof-yet/) Marathon Fusion's paper titled "Scalable Chrysopoeia via (n, 2n) Reactions Driven by Deuterium-Tritium Fusion Neutrons" (https://arxiv.org/abs/2507.13461) projects gold production of approximately 2 tonnes per gigawatt of thermal fusion power per year, based on neutron transport simulations. This market will resolve to "Yes" if the measured gold yield of a Marathon Fusion mercury-to-gold experiment is confirmed to be within 20% of the yield predicted for that experiment by Marathon Fusion's neutronics simulation, through at least one of the qualifying confirmation methods listed below, by December 31, 2026, 11:59 PM ET. Otherwise, this market will resolve to "No". A qualifying experiment is one in which stable gold-197 is produced from mercury using neutrons generated by deuterium-tritium fusion reactions (including deuterium-tritium neutron generators). The predicted yield is the number of gold-197 atoms that Marathon Fusion's neutron transport simulation (e.g., OpenMC) calculates for that specific experimental configuration, including its neutron source output, irradiation duration, target geometry, and mercury isotopic composition. The predicted yield must be publicly disclosed by Marathon Fusion or included in the publication or confirmation under consideration. The measured yield is the total number of gold-197 atoms produced by the irradiation, including gold-197 resulting from the decay of mercury-197 created during the irradiation. The measured yield will be considered within 20% of the predicted yield if the ratio of measured yield to predicted yield is at least 0.8 and no greater than 1.2. Confirmations that only establish that some gold was produced from mercury, that do not compare the measured yield against a simulated prediction for the same experimental configuration, or that compare against simulations other than Marathon Fusion's will not qualify. The qualifying confirmation methods are: (i) Peer-reviewed publication: a reputable peer-reviewed scientific journal publishes the measured yield of a qualifying experiment together with Marathon Fusion's simulated prediction for the same experimental configuration. Preprints and other publications that have not completed peer review will not qualify. (ii) Independent verification: a credible scientific institution unaffiliated with Marathon Fusion (e.g., a national laboratory, university research group, or accredited analytical laboratory) publicly confirms the measured yield of a Marathon Fusion experiment, based on its own measurements of material irradiated in that experiment or its direct observation of that experiment, and that measured yield is within 20% of Marathon Fusion's publicly disclosed prediction for that experiment. The confirmation must be published by the verifying institution itself; confirmations relayed only by Marathon Fusion will not qualify. (iii) Independent replication: researchers unaffiliated with Marathon Fusion reproduce an experimental configuration for which Marathon Fusion has publicly disclosed a predicted yield, measure a yield within 20% of that prediction, and make the results public. Marathon Fusion's employees, investors, and funders, including ARPA-E, Breakthrough Energy, the 1517 Fund, and Strong Atomics, as well as the authors of the paper referenced above, are considered affiliated with Marathon Fusion. Statements, social media posts, or press releases by Marathon Fusion or its affiliates, and media reports that only relay such claims, will not alone qualify. The resolution source for this market will be a consensus of credible sources and relevant scientific experts verifying the legitimacy of the qualifying confirmation. If there is ambiguity as to whether a confirmation under consideration for the resolution of this market is credible, this market may remain open until June 30, 2027, 11:59 PM ET, to allow for the publication of the relevant results in a reputable peer-reviewed journal. One such publication confirming that the measured yield is within 20% of Marathon Fusion's simulated prediction will be sufficient to resolve this market to "Yes", provided the underlying experiment was conducted by December 31, 2026, 11:59 PM ET. If no such paper is published by this delayed resolution time, this market will resolve to "No".