Sand Hill Angels
Sand Hill Angels is a Silicon Valley angel investor group founded in 2000 and based in Mountain View, California. Its members are seasoned technology entrepreneurs and executives who write seed and early-stage cheques across software, semiconductors, and life sciences. As of 2026, its one water company is Membrion, a ceramic-desalination-membrane maker it backed across two rounds.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
Sand Hill Angels is named for Sand Hill Road, the Silicon Valley street that became shorthand for venture capital itself. Founded in 2000, it is a club of operators rather than a fund: technology entrepreneurs and executives who pool their own money and judgement, write seed cheques, and take board seats themselves instead of handing the work to a managing partner.
Sand Hill Angels invests the way its members built their careers, in deep technology. Its cheques land in software, semiconductors, IT, and life sciences, usually at seed and early stage, and usually shoulder to shoulder with venture funds rather than against them. The group is explicit about being collaborative money: the angels who come in early, open doors, and help a founder reach the milestones that unlock a larger round.
Sand Hill Angels is not a water investor, and the data says so plainly: across a long portfolio, exactly one company touches water. That company is Membrion, a Seattle business that bakes ceramic into desalination membranes tough enough to pull clean water out of harsh industrial waste streams. Sand Hill Angels backed it alongside cleantech angel networks like E8, Sierra Angels, and Bellingham Angel Investors, the kind of syndicate that forms around a hard-science water bet.
Sand Hill Angels is worth watching, for a newcomer to water, less as a water fund and more as a generalist deep-tech net that occasionally catches a water company. The next Membrion, if it comes, will probably arrive the same way this one did: not as a water thesis, but as a materials-science startup that happens to solve a water problem.
Water Commitment Score
Compiled from official filings, third-party records, and direct intelligence from investors and founders, in Leviathan · recomputed monthly · as of Jun 2026.
How they invest
Portfolio · 1 water companies
Invests alongside
Highlighted = profiled on (don't) Waste Water.
Frequently asked
- What does Sand Hill Angels invest in?
- Sand Hill Angels invests in deep-technology startups, mostly at seed and early stage, across software, semiconductors, IT, and life sciences. Sand Hill Angels is a generalist group rather than a sector fund, and it typically co-invests with venture firms, adding member expertise, mentorship, and Silicon Valley connections alongside its capital.
- Who runs Sand Hill Angels?
- Sand Hill Angels is led by a member board. As of 2026, Markus Fromherz serves as President, Manthi Nguyen as Vice President, and Frank Willemsen as Treasurer, with active angels such as board director Amos Ben-Meir. The group is run by its investing members, not by outside fund managers.
- Is Sand Hill Angels a water-focused fund?
- Sand Hill Angels is not a water-focused fund. Sand Hill Angels is a generalist Silicon Valley angel group whose water exposure is a single investment: Membrion, a maker of ceramic desalination membranes. (don't) Waste Water rates the group's overall water commitment One-Off, reflecting that lone deal inside a broad deep-tech portfolio.
- Where is Sand Hill Angels based?
- Sand Hill Angels is based in Mountain View, California, in the heart of Silicon Valley. Founded in 2000, Sand Hill Angels draws its members from the Bay Area technology community and invests primarily in startups across Silicon Valley and the wider United States.
- Is Sand Hill Angels the same as Sand Hill Road or the Sand Hill Group?
- Sand Hill Angels is an angel investor group, not a Sand Hill Road venture firm or the consultancy Sand Hill Group. Sand Hill Angels shares only the Silicon Valley namesake: it is a membership network of individual angels writing their own cheques, founded in 2000 and based in Mountain View.