Investing Profile

Geoff Ralston(1)

VCInvestorAngel
Partner at Y Combinator
blog.ycombinator.com/author/g...Sunnyvale, California
Photo of Geoff Ralston, Partner at Y Combinator
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Networks Geoff is a member of
NewCo Network
1599 CONNECTIONS
NewCo Network
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NewCo Network
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NewCo Network
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Current Investing Position
Y Combinator Partner
Investment Range
$150K - $150K
Sweet Spot
$150K
Investments On Record
48

Geoff Ralston is on these Sector & Stage Rankings

Geoff Ralston's Investments On Record (41)

CompanyStageDateRound SizeTotal Raised
Asymmetric Security
Pre SeedJan 2026$4M
$4M
Co-investors: Chad Byers (Susa Ventures), Matt Clifford (Entrepreneur First), Charlie Songhurst
Locunity
Pre SeedJul 2025$230K
$230K
Rain Industries
SeedSep 2023$10M
$10M
Co-investors: Nancy Pfund (DBL Partners), Nat Friedman (C2 Investment), Kareem Dabbagh (VoLo Earth Ventures), Daniel Gross (C2 Investment), Immad Akhund (Y Combinator), Steve Blank (National Institutes Of Health), Dylan Field, John Collison, Patrick Collison
Turing College
Pre SeedFeb 2021$130K
$1.1M
Co-investors: Mikhail Seregine
Aesthetic
SeedApr 2020$3M
$6.1M
Co-investors: Michael Ma (Liquid 2 Ventures), Katey Caldwell (Twenty Two Ventures), Brad Flora (Y Combinator), Dalton Caldwell (Standard Capital), Ben Orthlieb (Linkedin), Brian Pokorny (SV Angel LLC), Ronny Conway (A Capital), Paul Buchheit (Y Combinator), Alex Sok, Ronny Conway, Sumon Sadhu, Adrian Aoun
Elpha
SeedNov 2019$1M
$2.1M
Co-investors: Michael Seibel (Y Combinator), Theresa Johnson (Uncommon Ventures), Leah Culver
Next Tech
SeedAug 2018$1M
$1M
Co-investors: Alireza Masrour (Plug & Play Ventures), Tim Brady (Y Combinator)
Shield Bio
Series AMay 2018$8M
SeedFeb 2017$4M
$12M
Co-investors: Vijay Pande (Andreessen Horowitz), Josh Buckley (Buckley Ventures), Zal Bilimoria (Refactor Capital), Riley Rodgers (Valia Ventures), Tim Brady (Y Combinator), Bryan Frist (Friále), Aneel Ranadive (Soma Capital), Enke Bashllari (Arkitekt Ventures), Jordan Fudge (Sinai Ventures), Justin Mateen, Sean Rad, Chris Anderson

Geoff Ralston's Experience

Advisor / Judge Four11, IncPresent
Partner Four11, IncPresent
Angel Investor and Small Company Advisor Four11, IncPresent
President Four11, IncPresent
Founder Four11, IncPresent
VP Engineering University of Washington Applied Physics LaboratoryPresent
VP Engineering yahooPresent
SVP/GM Communications yahooPresent
Advisor / Judge University of Washington Applied Physics LaboratoryPresent
Partner University of Washington Applied Physics LaboratoryPresent
Angel Investor and Small Company Advisor University of Washington Applied Physics LaboratoryPresent
President University of Washington Applied Physics LaboratoryPresent
Founder University of Washington Applied Physics LaboratoryPresent
Advisor / Judge Center for Rural Health LeadershipPresent
Partner Center for Rural Health LeadershipPresent
Angel Investor and Small Company Advisor Center for Rural Health LeadershipPresent
Founder Center for Rural Health LeadershipPresent
President Center for Rural Health LeadershipPresent
VP Engineering Center for Rural Health LeadershipPresent
VP Engineering The Academic College of Tel-Aviv, YaffoPresent
Advisor / Judge The Academic College of Tel-Aviv, YaffoPresent
CEO LalaPresent
Partner The Academic College of Tel-Aviv, YaffoPresent
Angel Investor and Small Company Advisor The Academic College of Tel-Aviv, YaffoPresent
President The Academic College of Tel-Aviv, YaffoPresent
Founder The Academic College of Tel-Aviv, YaffoPresent
VP Engineering NewCoPresent
Chief Product Officer yahooPresent
Advisor / Judge NewCoPresent
Partner NewCoPresent
Angel Investor and Small Company Advisor NewCoPresent
President NewCoPresent
Founder NewCoPresent
Various HPPresent
Founder SAIF - The Safe Artificial Intelligence FundPresent
Founder SAIF (Safe AI Fund)Present
President Y CombinatorPresent
Various Hewlett Packard EnterprisePresent
VP Engineering Four11, IncPresent
SVP/GM Communications Yahoo!Present
Advisor / Judge California Clean Tech OpenPresent
Angel Investor and Small Company Advisor Raltech, LLCPresent
Partner Y Combinator2011 - 2019
Founder Imagine K122011 - 2016
CEO Lala Media2007 - 2009
Chief Product Officer Yahoo!2003 - 2006
SVP/GM Communications Yahoo! Inc1999 - 2003
VP Engineering Yahoo!1997 - 1999
VP Engineering Four111995 - 1997
Various Hewlett-Packard1982 - 1992

Geoff Ralston's Education

Dartmouth College Bachelor of Arts (B.A.) Computer Science
Stanford University MS CS Computer Science and Electrical Engineering
INSEAD MBA Business