Researched and written in support of the Technology-to-Market (T2M) component of the ARPA-E fusion portfolio, this paper [Journal of Fusion Energy 40, 18 (2021); https://doi.org/10.1007/s10894-021-00306-4] is intended to be an informational resource both for ARPA-E fusion performers and for fusion investors, to help them focus on initial markets that can nurture fusion through its early deployments. The paper is also intended to clarify to the broader fusion research community the economic characteristics that fusion may need, at least initially, to succeed in the marketplace. Key findings are that fusion developers should consider focusing initially on high-priced global electricity markets and consider including integrated thermal storage, depending on techno-economic factors, to maximize revenue and compete in markets with high renewables penetration. Process heat and hydrogen production will be tough early markets for fusion, but may open up to fusion as markets evolve and if fusion’s levelized cost of electricity falls below 50 $/MWhe. Two spreadsheets are included on the journal website as supplementary materials, which readers may download and use to explore the bases and sensitivities underlying the analyses and quantitative results reported in the paper. A free, online-only version of the paper is available here: https://rdcu.be/cn8xD.