On Holding premarket jumps 7% on report Kylian Mbappé signs with On; Nike slips 1%

The market reaction reads as a direct read-across: a single endorsement is being treated as a competitive share shift between an upstart brand and an incumbent, which is a lot of weight for one athlete deal to carry. It matters most for how On's brand heat and Nike's endorsement moat are perceived, not for near-term revenue. Whether the reported signing is confirmed, and whether it shifts other athlete or sponsorship flows, is the open question.