John Brennan is the Managing Partner of Holly Ventures, a seed stage venture capital fund that invests in and supports cybersecurity entrepreneurs at their earliest stages. John has invested in over twenty security startups, with a focus on supporting founders from day one. Having previously served as a Senior Partner at YL Ventures, John has also held positions at Data Collective (DCVC), OCA Ventures, and Horsley Bridge Partners. His past portfolio work includes Axonius, Orca, Medigate, Hunters, Cycode, Vulcan Cyber, and many others. John holds an MBA from the University of Chicago and a Bachelor of Science from Trinity College in Connecticut.