Spiros “Sig” Segalas founded Jennison in 1969 alongside six co-founders. Sig was a pioneer in growth equity investing and was instrumental in establishing Jennison as an institutional equity and fixed income investment manager. Sig managed Jennison client portfolios for more than five decades and served as the firm’s President and Chief Investment Officer until his death in 2023. Sig began his investment career at Bankers Trust as a research analyst, before managing client assets. Prior to Bankers Trust, he worked in the shipping and construction industries and served as an officer in the US Navy. Sig received a BA in economics from Princeton University.