Arne H. Halleraker
Partner
FJ Labs
FJ Labs partner focused on marketplaces, B2B commerce, food, green tech, and gaming.
Bio
Professional summary
Jeff Weinstein is listed as a Partner at FJ Labs. The official team page provides his current role but not a full biography. A public announcement by Fabrice Grinda provides more background: Weinstein joined FJ Labs in 2017, previously spent four years at Lux Capital, earlier worked at Dunbar Capital, and studied Politics, Philosophy and Economics at the University of Pennsylvania. The same announcement says he had led more than 150 FJ Labs investments at that time and had worked on fintech, proptech, e-commerce rollups, LP fundraising, and investment-team leadership.
Investment focus
Stage, sector, and overall fit
Stage
pre-seedseedearly stageSeries Alater stage co-investment
Sector
marketplacesnetwork effectsfintechpropteche-commerce
Thesis
Marketplaces and network effects businessesFintechProptechE-commerce rollups
Notable companies
Selected portfolio companies the partner has backed
ProperlyMundiRazor GroupValoreoDwarfs.ioViajanet
How to approach
Framing and angles for outreach
Pitch framing
Lead with marketplace or network-effects fundamentals, then tailor to fintech, proptech, or commerce if relevant.
Personalization hooks
- 1Reference fintech, proptech, or e-commerce rollup relevance when applicable.
- 2Keep the ask concise and aligned with FJ Labs' fast co-investment process.
Recent signals
What the partner has said or done recently
FJ Labs official team page lists Jeff Weinstein as Partner.
Fabrice Grinda's public announcement described Jeff as co-heading the investment team and managing external LP fundraising at the time of promotion.
Background
Career, education, and skills
Career history
- FJ LabsPartner2017 - Present
- Kauffman FellowsFellow (Class 24)2019 - Present
- Milken InstituteYoung Leaders Circle2023 - Present
- MundiBoard Observer2020 - Present
- RiveBoard Director2023 - 2025
Education
- University of PennsylvaniaB.A., Politics, Philosophy, and Economics2007–2011
Skills
Venture CapitalMarketplacesLP RelationsInvestment Strategy
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