Marubeni

Warren Buffett began accumulating Marubeni — alongside the four other major Japanese trading houses — in August 2023 and subsequently raised the stake to 9.8% in 2024. In shareholder communications, he cited their diversified, asset-heavy portfolios, disciplined capital-return policies, and valuations that resembled Berkshire's own early-stage acquisition multiples more than those of a typical conglomerate. The position gives Berkshire passive exposure to global commodity flows and infrastructure cash flows.

Copper, iron ore, and liquefied natural gas anchor the resource portfolio. The Los Pelambres mine produces copper concentrates that feed Asian smelters, while Roy Hill ships iron ore to steel mills in Japan, China, and Korea. Marubeni also operates a fleet of LNG carriers that service long-term off-take agreements. Alongside metals and energy, the firm moves significant volumes of grain and forest products.

Its non-resource businesses include a residential-property development operation spanning China and India, an aircraft-leasing platform co-owned with Mizuho, and a venture arm exploring advanced air mobility and quantum-inspired AI compression. The firm also maintains the TradeWaltz digital-trade platform in Japan and holds strategic membership in the Japan Business Aviation Association via its aerospace unit.

Marubeni operates across a wide swath of the real economy but does not emphasize consumer-facing technology, biotech, or software-as-a-service businesses. Its venture activity — such as the April 2026 memorandum with Multiverse Computing — focuses on industrial applications rather than pure-play digital platforms. The firm's public statements concentrate on physical commodities, infrastructure, and adjacent industrial technology.