J Stern & Co

J Stern & Co

J Stern & Co launched in 2012 as the investment vehicle for the multi-generational wealth of the Stern family, French descendants of a banking lineage established by Jacob Stern in Frankfurt in 1805. The founding partners — Jérôme Stern and Christopher Rossbach — built the firm as a true partnership with no external shareholders, a structure designed to eliminate pressure for short-term exits or strategic pivots that would dilute the family's permanent capital horizon. The firm deploys capital through actively managed strategies covering global equities, multi-asset portfolios, corporate credit and emerging market debt. Each strategy runs high active share with low turnover, reflecting Rossbach's stated preference for holding quality businesses over 5-to-10-year windows. Alongside the liquid book, the firm participates in direct co-investments and private credit, with confirmed positions spanning FinTech, healthcare services, industrial technology, luxury, and energy transition assets. The partnership invests globally with activity documented across Europe, North America, Asia, the Middle East and Africa, and maintains offices in London, New York, Zurich and Malta to support sourcing. The team comprises 51 professionals including partners, senior directors and analysts, with reporting lines that keep all investment, client and operational activity under partner governance. A notable structural feature: the Stern family, partners and employees collectively represent 20% of total assets under management and advice, reinforcing alignment that most multi-family offices claim but few codify through ownership. No AUM figure is publicly disclosed; Altss estimates the firm oversees between $1.5 billion and $3.0 billion. The firm expanded its physical footprint in the last two years, opening its Malta office to complement existing operations in Switzerland and the United States. The firm's structural differentiator is its absence of external shareholders combined with succession architecture that embeds the next generation of partners inside the capital base. Unlike most multi-family offices that aggregate unrelated families into a single pooled vehicle, J Stern & Co operates as the direct extension of a single named family's balance sheet while selectively accepting external clients into the same strategies — creating an alignment stack that ties partner compensation, family wealth preservation and external client outcomes to identical portfolios.