SOSV
SOSV is a global deep-tech venture firm that runs the HAX and IndieBio startup accelerators, backing climate and health hardware and biology from the lab up. Water is occasional here: it arrives through HAX's hard-tech door, where Leviathan tracks one water company, PFAS-destruction startup Oxyle, across two deals. As of 2026, Leviathan rates SOSV's water commitment Occasional.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
SOSV is the venture firm behind HAX and IndieBio, two of the deep-tech world's best-known startup accelerators, and it was founded in 1995 by Sean O'Sullivan, the Cork-born engineer who helped build the mapping company MapInfo and is credited with coining the phrase cloud computing. SOSV runs as an accelerator-first investor: a small first cheque, then months of hands-on lab, engineering, and go-to-market help before a company raises a larger round. Water has never been a fund of its own here.
SOSV reaches water through HAX, its hard-tech program based in Newark, New Jersey. The one water company Leviathan tracks in the portfolio is Oxyle, an ETH Zurich spinout whose catalytic reactors destroy PFAS, the forever chemicals that conventional treatment plants cannot break down. SOSV backed Oxyle from its earliest rounds and has stayed in as the company scaled, the kind of patient hardware bet HAX was built for.
SOSV is, before anything, a climate and health investor, and water rides inside that climate thesis rather than standing on its own. In April 2024 SOSV closed its largest fund to date, the $306 million SOSV V, earmarking roughly seventy percent of it for climate tech. Water turns up where it overlaps hard tech and climate: destroying pollutants, treating wastewater, and the industrial end of the water cycle, not drinking-water utilities or digital-water software.
SOSV is not a water specialist, and its own scorecard says so plainly. Leviathan logs one water company across two deals, the firm has led none of those rounds, and it rates the water commitment Occasional. For a fund that runs more than a thousand founders through HAX and IndieBio, water reaches SOSV as deep tech first, so the next water bet will likely look like Oxyle: a hard-science company where cleaning water is the product, not the mission statement.
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 SOSV invest in?
- SOSV is a global deep-tech venture firm that runs two startup accelerators, HAX for hard tech and IndieBio for life science, and backs climate and health companies from pre-seed through later rounds. In water, Leviathan tracks one company, Oxyle, whose reactors destroy PFAS forever chemicals.
- Is SOSV a water-focused fund?
- SOSV is not a water-focused fund. It is a broad deep-tech investor, and water appears occasionally through its hard-tech accelerator HAX. Leviathan tracks a single water company, Oxyle, across two deals, and rates SOSV's water commitment Occasional rather than a dedicated water strategy.
- Who runs SOSV?
- SOSV was founded in 1995 by Sean O'Sullivan, its Managing General Partner, who earlier co-founded the mapping firm MapInfo. Its HAX hard-tech program, the one closest to water, is led by general partner Duncan Turner and chief science officer Susan Schofer; Pae Wu is a general partner who runs IndieBio.
- Where is SOSV based?
- SOSV is headquartered in Princeton, New Jersey, and operates globally. Its HAX hard-tech accelerator runs from Newark, New Jersey, and its IndieBio life-science program from San Francisco and New York, with further SOSV offices in Cork, Ireland, Pune, India, and Singapore.
- Is SOSV the same as HAX or IndieBio?
- No. HAX and IndieBio are SOSV's two accelerator programs, not separate firms. SOSV is the parent venture capital firm that funds and runs both. Water companies such as Oxyle reach SOSV through HAX, its hard-tech program, rather than through the IndieBio biology track.