Kimberly Pirtle, a fast-rising auctioneer at Sotheby’s, has left the company to start her own firm, Gabriel Advisory Group, a practice that aims to bridge art advisory and cultural philanthropy. Pirtle, who worked in Sotheby’s collectors group and quickly moved into auctioneering, said the idea grew out of a gap she kept running into with clients. At the auction house, the focus was clear: transactions. But many of the collectors she worked with were thinking more broadly—about artists, institutions, and how their collecting fit into a larger ecosystem. Related Articles “They were intentional,” she said of her clients, describing collectors who wanted to support artists and institutions, and not solely acquire objects. That kind of thinking, she found, didn’t fit neatly inside the structure of an auction house. Gabriel Advisory Group is her attempt to formalize a different approach. The firm works across both the primary and secondary markets, advising collectors on acquisitions while also guiding philanthropic strategy and institutional engagement. For some clients, that means navigating auctions and gallery relationships. For others, it means shaping …