Greg Castle is a former consumer marketing and growth operator who led user acquisition at companies like Glassdoor and Chartboost before becoming a venture investor, giving him hands-on experience with performance marketing that most career financiers lack. He's known for deep specialization in spatial computing and AR/VR, where he was one of the earliest individual investors in Oculus at the seed stage and now focuses on frontier human-computer interfaces as a domain expert rather than a generalist investor.

• Deep expertise and conviction in virtual and augmented reality, largely stemming from an early investment in Oculus. He closely follows hardware advancements, noting that improvements in weight, battery life, and ergonomics are critical hurdles that still need to be cleared for mass adoption, while expressing bullishness for the next couple of years.
• Strong focus on defense technology and American reindustrialization. He actively promotes and invests in companies that support national security and manufacturing, praising founders like those at Anduril or NOX Metals who are building physical technologies to maintain democratic advantages.
• Values face-to-face interaction and customer obsession over standard VC formalities. He advises founders to get on planes to close deals rather than relying on video calls and publicly commended a portfolio founder for canceling a meeting with him to prioritize a customer engagement instead.
• Actively deploying capital at the pre-seed stage with check sizes ranging from roughly a quarter to three-quarters of a million dollars. He uses his platform to source deals directly, asking his network to tag founders who need funding, particularly those building in frontier tech or deep tech sectors.
• Appreciation for concise and contextual communication in investor updates. He specifically noted how helpful it is when founders include a brief reminder of what the company does at the top of their newsletters, as it helps investors who track many companies stay oriented.
• Personal dedication to Brazilian Jiu-Jitsu as a daily routine and networking tool. He credits early morning training sessions with setting a productive tone for the day and even extends open invitations to others visiting Los Angeles to meet up for a sparring session.