Business 100 – 2016

Sean Costello/Mayer Park Capital

Sean Costello is the founder and CEO of Mayer Park Capital, a private investment management firm based both in New York and London. With over 20 years of financial markets experience in the U.S. and Europe, Sean leads Mayer Park’s practice servicing some of the most prominent global family offices in the Americas, Europe, and Africa. He has previously worked in senior roles at firms including Morgan Stanley, Lehman Brothers, and Barclays.

Born in Holyoke, Massachusetts, Sean is the great-grandson of four Irish expats from counties Kerry (on his father’s side) and Cork (on his mother’s). Currently, he and his husband, Sean Mahon (a native Dubliner), live between New York and Dublin. “Growing up in Holyoke, I have always been proud of my Irish heritage and the values and work ethic it has taught me,” he says. “Now, living in Dublin, I can actually see those fundamental traits in the Irish people.”

Sean obtained his B.A. from the University of Pennsylvania and an M.B.A. from the Fuqua School of Business at Duke University, where he also sits on the European advisory board. He holds membership with the Irish Network NYC and Irish Network Dublin.