43

What 43 does

43 is a San Francisco-based, Day 0 venture capital firm founded in 2023 by partners Dustin, Anabel, and Soso. The firm invests $250,000–$500,000 in founders before they have a product or any market traction, positioning itself as a pre-seed alternative to cohort-based accelerators such as Y Combinator. Unlike traditional accelerators, 43 runs no batches, no curriculum, and no demo day; each founder receives a 1:1 relationship with a partner for the life of the company, along with hands-on support for strategy, operations, and future fundraising, plus access to the fund's San Francisco workspace.

The firm's business model is equity-driven: 43 takes ownership stakes in portfolio companies and earns returns as those companies raise subsequent rounds or exit. Its revenue depends entirely on the performance of its ~40+ portfolio companies and is not generated through management fees, carry distributions, or service revenue within the disclosed period. The firm sources deal flow through a rolling website application (no pitch deck required; 48-hour response SLA; 2–4 week decision timeline) and accepts only ~5 founders per partner per year, explicitly trading scale for selectivity. Notable portfolio companies include Insight Health ($11M Series A, April 2026), Onton ($7.5M seed, November 2025), and Hypernatural ($9.2M raised through mid-2025).

From a technology standpoint, 43 is not a software company and develops no proprietary technology stack. Its competitive differentiation rests on partner brand, operating network, and bespoke service delivery rather than on platforms, APIs, or AI systems. The portfolio itself spans AI-native vertical SaaS (clinical agents, video generation, AI shopping), insurance, fintech, developer tools, and consumer products, but in-house AI capability at the firm level is nil.

Name

43

Legal name

43

Website

https://43.io

Company type

Private

Founded year

2023

Operating status

Operating

Headcount range

1–10 employees

Short description

43 is a San Francisco-based Day 0 venture fund founded in 2023 by three partners that invests $250K–$500K in pre-product founders, providing bespoke 1:1 partner support rather than cohort-based accelerator programming, and earning returns through equity stakes in its 40+ portfolio companies.

Ownership category

akta.pro rank

Product category

Venture Capital / Pre-Seed Investment

NAICS

Other Financial Investment Activities (5239)

SIC

Investment Advice (6282)

akta.pro primary industry

Early-Stage Venture Capital (Series A/B) (FSANAAAB)

akta.pro secondary industry

Accelerators & Incubators (Investor-Operated) (FSANAAAM)

Keywords

• Pre-seed venture capital
• Day zero investing
• Founder support services
• Startup accelerator alternative
• Early-stage equity funding

Headquarters

HQ city

San Francisco

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Infrastructure, Marketing or Sales

Revenue model

1. Equity Investment Returns: 43 provides $250K–$500K in initial investment to early-stage founders in exchange for equity in the company. The firm's revenue is derived from returns on these equity positions as portfolio companies grow, raise subsequent funding rounds, or exit.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels1 record

Core offering

43 is an accelerator alternative and pre-seed investment firm that invests $250,000 to $500,000 in founders at "Day 0" — before they have built a product or achieved market traction. In exchange for equity, portfolio founders receive 1:1 bespoke support from a partner for the life of the company, hands-on fundraising guidance, and access to a San Francisco workspace, with no cohorts, demo days, or curriculum.

Product overview

43 is an accelerator and pre-seed investment firm that operates as an alternative to traditional accelerators by investing $250K-$500K at Day 0 — before any product or market traction exists. The firm offers a single unified investment offering coupled with bespoke, 1:1 partner support rather than cohort-based programming. Portfolio founders receive hands-on operational guidance, San Francisco workspace access, and fundraising assistance to prepare for subsequent funding rounds. The application platform serves as the entry point, requiring no pitch deck and responding within 48 hours for qualified candidates.

Differentiator

Problem solved

Functional benefit

Products and services

• 43 Investment Program A pre-seed investment offering that provides $250,000 to $500,000 of equity capital to founders at Day 0, before they have built a product or achieved market traction, coupled with bespoke 1:1 partner support for the life of the company. Designed as an alternative to traditional cohort-based accelerators, with no demo days, curriculum, or batch timing.
• 43 Application Platform A rolling, year-round web-based application portal through which prospective founders submit their background, idea, progress, and prior funding to be considered for the 43 Investment Program. Requires no pitch deck and commits to a 48-hour response for applicants the firm wants to meet.

Quantifiable outcome

• 43 has backed 40+ founders at Day 0 across diverse sectors including healthcare AI (Insight Health), video creation (Hypernatural), and shopping AI (Onton), with portfolio companies going on to raise significant follow-on funding.

Segments1 record

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Scale indicators3 records

Recent moves5 records

Expansion highlights4 records

Direct peers

• Y Combinator: The dominant early-stage accelerator, investing in pre-seed/seed founders at the very earliest stages with standard deal terms and cohort-based programming. Directly comparable as the benchmark Day 0/seed capital provider.
• Pioneer Fund: A pre-seed focused venture fund that invests at the earliest stages with concentrated portfolios and partner-led support. Closely matches 43's model of small checks at Day 0 with bespoke founder attention.
• Pear VC: Pre-seed and seed investor focused on founders at the earliest stages, including AI and healthcare. Directly comparable in stage, check size, and Day 0 philosophy, and a co-investor alongside 43 in portfolio companies like Insight Health.
• South Park Commons: A founder-first community and fund that supports pre-idea and pre-product founders with an alternative to traditional accelerators. Highly comparable as a non-cohort, bespoke support model for Day 0 founders.
• Afore Capital: A pre-seed focused venture firm investing before product and traction with concentrated partner attention. Direct peer in stage, philosophy, and check size range.
• Antler: Global early-stage investor and founder residency program that invests at Day 0 before a product exists. Directly comparable in stage and approach, though Antler operates cohort-based residencies globally.

Broad incumbents

• Techstars: Established global accelerator network running cohort-based programs with mentorship and demo days. Comparable as an early-stage accelerator, though 43 explicitly differentiates against its cohort model.
• 500 Global (500 Startups): Large global accelerator and seed fund investing across geographies and stages at the earliest phases. Comparable as a broad pre-seed/seed capital provider, though at much larger scale than 43.

Emerging players

• Susa Ventures: Early-stage venture fund with concentrated pre-seed and seed investments, often partnering with operators. Comparable as an early-stage investor with an operator-led model, though typically with slightly later-stage involvement.
• On Deck: Founder community and fund providing capital and programming to early-stage founders and operators. Comparable as a founder-support platform at the earliest stages, though oriented more around community than direct Day 0 checks.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat3 records

Key risks5 records

Key highlights5 records

Customer concentration

• LinkedInlinkedin.com/company/43-ventures

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments13 records

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about 43