Seth Rosen
InvestorVenture Partner at Western Technology Investment
Boston, Massachusetts
Writes $100K – $5M checks · typically $1.5M
About
Seth Rosen is CEO of CustomMade, an e-commerce marketplace for custom products that he acquired in 2009, raised $30M in venture funding for, and repurchased and relaunched in 2015 to become the world's largest online custom jeweler. He also acquired and operates International Gem Society and Ganoksin, two niche websites in gemology and jewelry manufacturing with over 30M annual visitors combined. Rosen serves as a Venture Partner at Western Technology Investment focused on the Boston market and previously held the position of partner at Meredith & Grew in commercial real estate capital markets; he holds an MBA and MST from Bentley University and an undergraduate degree from Boston University.
Experience
- Standard DentalBoard Observer - Lender Representativecurrent2025 — presentMiami, Florida, United States
- Gold Words, Inc.Board Observer - Lender Representativecurrent2024 — presentAkron, Ohio, United States
- eCom Brand HoldingsBoard Observer - Lender Representativecurrent2023 — presentAkron, Ohio, United States
- Western Technology InvestmentVenture Partner | Private Credit, Special Situations & Direct Lending | Operator Backgroundcurrent2021 — presentBoston, MA
- CustomMadeFounder & CEOcurrent2015 — presentCambridge, Massachusetts
- CustomMadeCo-Founder, President & Board Chairman2009 — 2015Cambridge, MA
- International Gem SocietyOwnercurrent2012 — presentLincoln, Massachusetts
- The Ganoksin ProjectOwnercurrent2016 — presentLincoln, MA
- Boston UniversityFaculty Member – CPE Program (Capital Markets Class)2008 — 2009Boston, MA
- Colliers International, Boston (fka Meredith & Grew, Inc.)Vice President & Shareholder2004 — 2009Boston, MA
- East Coast Realty, Inc.Manager2001 — 2004Boston, MA
Skills & more
Microsoft Excel2ExcelEntrepreneurship57Venture Capital42Jewelry and GemologyStrategy45Financial Modeling22Financial Analysis18Start-ups14Private Equity13Online Marketing8SEO5
+12 more
E-commerceCapital MarketsFinanceBusiness StrategyMarketingValuationSalesBusiness DevelopmentCorporate FinanceJoint VenturesAnalysisLeadershipLanguages Spanish
- Massachusetts Notary Public — Commonwealth of Massachusetts
- Massachusetts Real Estate Broker — Board of Registration of Real Estate Brokers and Salespersons
- Series 65 - Uniform Investment Adviser Law Examination — FINRA
From Seth's professional profile.
Colleagues at Western Technology Investment
Frequently asked questions
- Who is Seth Rosen?
- Seth Rosen is CEO of CustomMade, an e-commerce marketplace for custom products that he acquired in 2009, raised $30M in venture funding for, and repurchased and relaunched in 2015 to become the world's largest online custom jeweler. He also acquired and operates International Gem Society and Ganoksin, two niche websites in gemology and jewelry manufacturing with over 30M annual visitors combined. Rosen serves as a Venture Partner at Western Technology Investment focused on the Boston market and previously held the position of partner at Meredith & Grew in commercial real estate capital markets; he holds an MBA and MST from Bentley University and an undergraduate degree from Boston University.
- Where does Seth Rosen work?
- Seth Rosen is Venture Partner at Western Technology Investment.
- What check size does Seth Rosen write?
- Seth Rosen typically writes checks of $100K – $5M.
- Where did Seth Rosen go to school?
- Seth Rosen studied at Boston University (Bachelor's Degree, Psychology); Bentley University (Master of Science in Taxation - MST); Bentley University (Master of Business Administration - MBA, Concentration in Taxation & Structured Finance).
Founder mafias
Boston University mafia69
Also came through, then founded or led a company.
Arjun SethiBA (WIP)Founded Termina +2Oleg RogynskyyBachelor's DegreeFounded UFORCE Acquired +2Ben ZisesFounded Superangelsyndicate +2Sanjiv SanghaviBAFounded Texture +2Brandon PatonBAFounded Glider +2James LindenbaumBS in Business ManagementFounded Ink & Switch +1
+ 62 more
Bentley University mafia8
Also came through, then founded or led a company.
Andrew SpellmanBachelor's DegreeFounded FifthdownHans ChristensenBachelor of Science - BSFounded Garderos GmbHMarcio Lempert---Founded Red AccessPatrik OuterickyBSFounded SimpleLegalSteve AlbarranBSFounded Confident LIMSDeepak ChhuganiBachelor of Science (B.Sc.)Founded Nuvocargo
+ 1 more
Western Technology Investment mafia2
Also came through, then founded or led a company.
Same school
Also attended Boston University314
Aydin SenkutFounder & Managing Partner at FelicisVinnie LauriaFounding Partner at Golden Gate VenturesJeff GrammerPartner at Rho VenturesJoe HayesInvestor at LightbankGil GorenPartner at 83NorthJames LindenbaumCo-founder at Heavybit
+ 308 more
Also attended Bentley University128
Jessica DowdInvestor at OpenView Venture PartnersBrett RippergerDirector, Investor Reporting & Business Analytics at Sapphire VenturesAndrea ScholzSenior Executive Assistant at Sapphire VenturesAva BrunelleInvestor at Third Rock VenturesGabriella WilliamsInvestor at Third Rock VenturesGreg O'BrienInvestor at Third Rock Ventures
+ 122 more
Shared employers
Also worked at CustomMade1
Also worked at Boston University44
William WooImpact at Non Sibi VenturesYousuf ShehadiTalent at AudaciousMatt MorrisSenior Associate at Hitachi VenturesRachel HaotChief of Staff at BedrockCorey ThomasChairman & CEO of Rapid7 at Underscore VCMay AlSalehInvestment Associate at Outliers VC
+ 38 more
Also worked at Colliers International, Boston (fka Meredith & Grew, Inc.)26
Casy van MaanenAssociate at GTMfundHarry BrodyInvestor at Maor InvestmentsMarius EisfeldAssociate at Seed+SpeedGraham CujeSenior Associate at Harbert Growth PartnersJoanna LambertCOO, Olo at The 98Matthias LeubeAdvisor, Founder of Ecouity GmbH at Realyze Ventures
+ 20 more