Max Mullen
About Max Mullen
Max Mullen is a co-founder of Instacart, the grocery delivery and pickup company launched in 2012. He is based in San Francisco and originally comes from Los Angeles. PitchBook's profile says he spent more than 11 years building Instacart and led teams focused on culture and employee experience.
On his X profile, Mullen describes himself as an Instacart co-founder and startup investor. A pinned post says he stepped back from the day-to-day at Instacart to focus on investing full-time. He discussed that move, Instacart's history and his approach to early-stage investing on Jack Altman's Uncapped podcast.
The podcast listing says he also runs a founder community in San Francisco called Workshop.
Mullen invests as an individual, not through a fund. Crunchbase lists 26 investments for him, with 0 lead investments and 0 exits. Other databases count differently. PitchBook shows 71 investments and 52 portfolio companies, and Tracxn shows 52 portfolio companies. Podcast and profile descriptions say he has invested in or advised more than 100 startups.
His non-AI investments include fintech and software companies. Boring Business Nerd lists Mercury, Deel, Newfront, AtoB, Census, Clearbit and Pocus among his select investments. He was also one of the angels in Float Health's $10 million Series A, led by Canvas Ventures, which was reported in 2024.
Mullen's own pages do not say whether he leads rounds. Crunchbase shows no lead investments. In public announcements he appears in lists of angels or investors alongside the lead funds.
Crunchbase data on Lounge shows 18 AI investments since 2023. The AI companies listed are Particle.News, Owner, Gumloop, Multiply, PostgresML, Hero Assistant, Unusual AI, JustPaid, Ghost, Willow Voice, Openlayer and Highstock.
Gumloop is the best documented. It raised a Series A in January 2025, led by Nexus Venture Partners with First Round Capital and Y Combinator. BetaKit and TechCrunch both name Mullen among the angels in that round. Gumloop's CEO told BetaKit the company wanted investors who were previous founders and could advise on scaling.
Particle, the AI-powered news app, named Mullen among the angels in its announcement of a $10.9 million Series A led by Lightspeed Venture Partners. Owner's Series B investor memo lists him among its investors, with his Instacart affiliation. Crunchbase lists him as a seed investor in Multiply.
On X he congratulated Highstock after its $30 million Series A led by a16z, calling it an OG Instacart team. Highstock's founder is Camille van Horne.
The public record points to early-stage investing, mostly seed. StartupFundraising.com describes his typical investments as ranging from seed to Series A. It also says he focuses on software services, AI and workforce tools and often backs founders from the Instacart alumni network. That is a third-party summary, not something Mullen has published himself.
His portfolio covers AI automation, AI applications and infrastructure, fintech, HR software and marketplaces. He is based in San Francisco and invests in companies in several countries. Gumloop was founded in Vancouver and was relocating to San Francisco when it raised its Series A.
Mullen has not published a check size, ownership targets or a formal thesis that we could find. Nordic9 reports an average round size for his investments, but that is the size of the rounds he joined, not his own check. He has said publicly that he appreciates founders who send investor updates on time (X, November 2022).
- Gumloop: no-code AI workflow automation platform. Mullen was an angel in its January 2025 Series A.
- Particle.News: AI-powered news app. Mullen was an angel in its $10.9 million Series A, led by Lightspeed.
- Owner: lists Mullen among its investors in its Series B investor memo.
- Multiply: Crunchbase lists Mullen as an investor in its seed round.
- Highstock: led by Camille van Horne, who previously worked at Instacart. Raised a $30 million Series A led by a16z, and Mullen publicly congratulated the team.
- Mercury: banking for startups. Named as one of his investments in the Uncapped podcast listing.
- Float Health: home-based nurse staffing startup. Mullen was an angel in its 2024 Series A, led by Canvas Ventures.
- PostgresML, Hero Assistant, Unusual AI, JustPaid, Ghost, Willow Voice and Openlayer: AI companies in his Crunchbase portfolio.
- x.com/Max
- crunchbase.com/person/max-mullen
- pitchbook.com/profiles/investor/109672-03
- podcasts.apple.com/md/podcast/uncapped-47-max-mullen-from-instacart/id
- techcrunch.com/2025/01/10/gumloop-founded-in-a-bedroom-in-vancouver-le
- betakit.com/work-automation-platform-gumloop-raises-24-5-million-serie
- particlenews.medium.com/particle-raises-series-a-to-accelerate-develop
- owner.com/b
AI portfolio
Investing activity
Max Mullen has made 26 investments according to Crunchbase. 18 of those investments since 2023 were in AI companies, including Particle.News, Owner, Gumloop, Multiply and PostgresML.
Max Mullen appears in 3 AI deals tracked by the Lounge deals desk. The rounds are mostly Seed, with a median round size of $9M and the largest at $10M. The most recent are ChampAI (Seed, $8.5M, May 2026), Multiply (Seed, $9.5M, Mar 2026) and Unusual AI (Seed, $3.6M, Jan 2026).
Max Mullen most often invests alongside Redpoint Ventures, SV Angel, JJ Zhuang and defy.vc, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Max Mullen
Who is Max Mullen?
Max Mullen is a co-founder of Instacart and an angel investor based in San Francisco. He says he stepped back from day-to-day work at Instacart to invest full-time.
What AI startups has Max Mullen invested in?
Crunchbase data lists 18 AI investments since 2023. They include Gumloop, Particle.News, Owner, Multiply, PostgresML, Hero Assistant, Unusual AI, JustPaid, Ghost, Willow Voice, Openlayer and Highstock.
What stage does Max Mullen invest in?
He is an early-stage investor. A third-party profile describes his investments as ranging from seed to Series A, and his documented rounds are mostly seed and Series A.
What is Max Mullen's check size?
He has not published a check size and we found no reliable public figure. Database counts of his investments vary, so treat any figure you see with caution.
Does Max Mullen lead rounds?
Crunchbase shows 0 lead investments. In public announcements such as Gumloop's and Particle's Series A rounds, he is listed as an angel alongside the lead funds.
How can founders contact Max Mullen?
He is on LinkedIn at linkedin.com/in/maxmullen and on X as @Max. His personal site is maxmullen.com. A warm introduction from someone in his network is the most reliable route.
Is Max Mullen an angel investor?
Yes. Max Mullen invests personally as an angel. Crunchbase counts 26 investments.
What AI companies has Max Mullen invested in?
Max Mullen's AI investments include Particle.News, Owner, Gumloop, Multiply, PostgresML, Hero Assistant, Unusual AI and JustPaid. The 3 rounds on Lounge are listed on this page with amounts, dates and co-investors.
Where is Max Mullen based?
Max Mullen is based in San Francisco, United States.
What stage does Max Mullen invest at?
In the rounds tracked on Lounge, Max Mullen has invested at Seed, with a median round of $9M.