The LVMH and Dior boss has invested in Maxime Simoens eponymous brand. The 27-year-old French designer was at one point rumoured to be in the running for the top job at Dior, alongside a number of more experienced candidates.
The scope of Arnaults investment in Simoens brand has not been disclosed, but insiders confirmed the acquisition.
They do believe in him, and want to finance him, one source told WWD, suggesting that Arnault could view Simoens as an eventual candidate for a job with a bigger luxury brand.
The move represents a departure from Arnaults recent acquisitions. Most recently, the luxury titan spent $6bn to acquire Bulgari; he has also built a sizeable stake in Hermès. His last investment in an untested fashion brand was in 2009, when LVMH purchased a 49% stake in Ali Hewson and Bonos Edun.
Simoens worked for designers including Elie Saab, Jean Paul Gaultier, Nicholas Ghesquière and John Galliano before shifting his focus to his own brand. He recently concluded a collaboration with French fashion brand Leonard, saying the departure left him free to concentrate on new projects.