Magrathea Metals is an American technology company focused on rebuilding domestic and Western magnesium metal supply through a proprietary next-generation electrolytic process. The company produces clean magnesium metal from seawater and brines, addressing a critical vulnerability in the U.S. supply chain: China currently controls approximately 95% of global magnesium production, while the United States and Europe produce none. Magrathea has emerged as the leading ex-China magnesium project by capital raised and commercial traction, having secured over $100 million in backing from venture capital, government, and industry partners. The company's mission is rooted in national security and strategic industrial resilience, as magnesium is an essential embedded material in aerospace, defense, automotive, titanium production, and steelmaking. Magrathea has received a $19.6 million Defense Production Act Title II investment to fund its pilot and Commercial Phase I through to commercial-scale technology. It has also formed a joint venture with Tetra Technologies (NYSE: TTI) to develop a brownfield-permitted smelter site in Arkansas, leveraging existing industrial infrastructure. What sets Magrathea apart is its proprietary solution to the process technology bottleneck that has caused every previous non-Chinese magnesium venture to fail, specifically the dehydration of magnesium salts and electrolysis to metal. The company reports up to 50% reductions in capital and operating expenditure compared to legacy electrolytic methods, and has filed 11 provisional patent applications. Its clean production approach, strategic government partnerships, and category-leading position make it a distinctive player in the critical minerals and green materials sector.