Day One Entrepreneurs & Partners

Day One Entrepreneurs & Partners

Co-founder and President Michel de Guilhermier built Day One Entrepreneurs & Partners on an entrepreneurial rather than strictly financial foundation, drawing on his experience founding Photobox and Juan Hernandez’s track record at Club-Internet. The firm secured €50 million from the Leclercq family, creators of the Decathlon sporting-goods empire, in 2017, supplemented by partner capital from real-estate investor Christophe Courtin. The structure gives Day One a permanent-capital feel within a venture framework, insulated from traditional fund-cycle pressures. Day One operates as a generalist investor across enterprise software, consumer technology, and digital health, targeting seed and start-up stages where it can commit several million euros over a holding period. The firm prefers concentrated positions and works closely with Bpifrance on co-investments, including a shared bet on legal-tech company LegalPlace. Geographic focus remains on France and continental Europe, where seasonal gatherings like the annual “Day One Days” at Château de Rosay reinforce a curated network among portfolio founders. The team, anchored by de Guilhermier, Hernandez, and Courtin, draws additional connectivity through de Guilhermier’s membership in Angel Square and the HEC Paris alumni network. In 2016 the firm deepened its real-asset capabilities when Courtin joined as a shareholder and partner, folding his Courtin Real Estate expertise into the platform. The vehicle eschews the fund-of-funds model in favor of direct, relationship-driven deal-making that mirrors the operational DNA of its founding families. Unlike most seed-stage firms organized around limited-partner blind pools, Day One’s scaffolding comes from a single industrial-family commitment that functions as a quasi-evergreen balance sheet. This patient-capital architecture allows the firm to sustain multi-year bets without the forced exit timelines of conventional venture funds, positioning it closer to a hybrid family-office incubator than a classic French VC partnership.