Joe Hammill spent a decade at Citi in equities and credit, building their top-ranked digital platform. He joined Stephanie Rieben at a Series A fintech before starting Diadem together. He has a bachelor's degree from SUNY Albany.

After a decade on Wall Street and four years in fintech, Stephanie Rieben co-founded Diadem Capital with Joe Hammill, her Citi colleague. She has an MBA from Georgetown and a BS from Lausanne Bschool.