Mathieu who?

Mathieu Guyot-Sionnest is an independent automobile advisor with a background spanning auction houses, market strategy, and collectible vehicles across cars and motorcycles. He has worked closely with collectors, institutions, and international clients, advising on pricing, positioning, and transaction strategy within both traditional and online auction environments.

Mathieu managed the live sales of more than 1000 collectible vehicles while working at auction houses, including about 150 from personal consignment and conducted the appraisal of more than 300 vehicles, including Collections of well-known collectors and institutions such as the Petersen Museum in Los Angeles, CA.

Mathieu is also a veteran vintage car racer and experience Concours d’Elegance Judge, experiences that inform a practical, first-hand understanding of vehicles beyond their market value alone. This perspective shapes his approach to advising on quality, originality, and long-term collectability, while having access to virtually any collectors across the globe.

Based between Los Angeles and Paris, Mathieu works with collectors seeking clear, informed guidance on acquisitions, sales, and the long-term coherence of their collections.