# Joe Greenstein

> Joe Greenstein is a seed investor at Innerspace (San Francisco) backing Software and Mobile. See 24 investments, check sizes, portfolio. Updated Aug 2026.

- Type: Angel Investor
- Fund: [Innerspace](https://shizune.co/investors/profile/innerspace-2)
- Location: San Francisco, United States
- Total investments: 24
- Last investment: Dec 2024
- Lead investor: 0%
- Last updated: Aug 2026
- LinkedIn: http://www.linkedin.com/in/joegreenstein
- X (Twitter): https://twitter.com/greenstein_joe
- Facebook: https://www.facebook.com/joe.greenstein

Joe Greenstein is a seed investor at Innerspace in San Francisco focused on Software and Mobile. Joe Greenstein is the Co-Founder and Assistant Zookeeper at Innerspace. He attended the Wharton School and the University of Pennsylvania.

## Round sizes

| Stage | Round size |
| --- | --- |
| Seed | $465k–$5.5M |
| Pre-Seed | $650k–$2M |
| Series A | $1.2M–$14M |

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Software | 6 | 25% |
| Mobile | 4 | 17% |
| Internet | 4 | 17% |
| Health Care | 4 | 17% |
| FinTech | 3 | 13% |

61 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 11 | 46% |
| Series A | 6 | 25% |
| Pre-Seed | 3 | 13% |
| Funding Round | 2 | 8% |
| Series B | 1 | 4% |

6 stages tracked in total.

### Country

| Country | Investments | Share |
| --- | --- | --- |
| United States | 21 | 88% |
| India | 1 | 4% |
| Israel | 1 | 4% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Momentum | Momentum is an OS/inbox and copilot for anyone who runs a pipeline (sales, fundraising, success, hiring, etc). Powered by behavioral science, useful AI, and thoughtful people. |  | Seed | Dec 01, 2024 |  |
| Gently | Gently (fka Wearloom) is the demand layer for secondhand shopping. Secondhand shoppers come to Wearloom to find the best listings from resale sites like Poshmark, Depop, eBay, and more! Wearloom now serves 10,000+ secondhand shoppers everyday. | $2M | Pre-Seed | Sep 26, 2022 |  |
| Reveri | Reveri’s vision is a world where anyone, anywhere, has access to the immediate benefits of self-hypnosis, and can use it to cope effectively with a variety of physical and/or mental health issues, such as anxiety, lack of focus, sleeping problems, tackling bad habits like smoking or alcohol drinking, among others. Backed by 45 years ofclinical research and practice, Reveri was created by Dr. David Spiegel, a world-leading psychiatrist at Stanford University and one of the most respected experts in the field of hypnosis. Reveri offers hypnosis sessions through a clinically-backed self-hypnosis app, serving personalized, guided sessions with the vision to mirror the experience of an in-person therapist, unlocking the power of their own minds to work towards their goals or solve a particular problem. | $3.8M | Seed | Feb 09, 2022 |  |
| Topknot | Topknot is the online personal development platform for women. With a unique blend of independent exercises and peer group feedback, Topknot supports women on their journey to building the life they want. By teaching skills rooted in coaching and mindfulness, Topknot's intentional interaction model empowers women to address what’s top of mindtoday, while also equipping them for tomorrow’s challenges–providing the space for processing, perspective, and accountability that leads to meaningful change. | $650K | Pre-Seed | Dec 16, 2020 |  |
| Maslo | Maslo is a new category defining technology. The platform captures and processes unstructured signals like audio, video, and biomarkers to infer mental states, behaviors, and change in people over time. | $1.9M | Pre-Seed | Nov 19, 2019 |  |
| Dost Education | Dost builds software, audio content, and toolkits that make it easy, fun and addictive for parents of any literacy level to boost their child’s early development. |  | Seed | Mar 21, 2017 |  |
| Juvo | Juvo was founded with an overarching vision: to establish financial identities for the billions of people worldwide who are creditworthy, yet financially excluded. In partnership with mobile network operators, Juvo’s proprietary Identity Scoring technology uses data science, machine learning and game mechanics to create an identity-basedrelationship with anonymous prepaid users, opening up access to otherwise unattainable mobile financial services. Juvo is a privately held company backed by global business leaders and luminaries in the world of tech, mobile and finance. Its executive team comprises accomplished industry leaders across the data science, consumer internet, financial services and mobile telecom fields. | $14M | Series A | Sep 09, 2016 |  |
| Bloomberg Second Measure | Bloomberg Second Measure is a technology company that analyzes billions of anonymized purchases to help some of the world’s largest brands and investment firms answer real-time questions on company performance and consumer behavior.We’re based in the Bay Area with an office in New York, and are proudly backed by Bessemer Venture Partners, GoldmanSachs, Citi Ventures, Jefferies Investment Group, Y Combinator, and other top investors. | $5.4M | Seed | Apr 05, 2016 |  |
| Triplebyte | Triplebyte is a recruiting and technical screening platform for tech companies. They believe the current technical hiring process doesn't do enough to help engineers show their strengths. They're dedicated to building a better process. You can read more about their views on hiring in their manifesto. | $3M |  | Sep 28, 2015 |  |
| Triplebyte | Triplebyte is a recruiting and technical screening platform for tech companies. They believe the current technical hiring process doesn't do enough to help engineers show their strengths. They're dedicated to building a better process. You can read more about their views on hiring in their manifesto. | $3M | Seed | Sep 28, 2015 |  |

10 of 24 investments shown.

## Co-investors
- [SV Angel](https://shizune.co/investors/profile/sv-angel) — VC Fund, 6 deals together
- [Felicis](https://shizune.co/investors/profile/felicis-ventures) — VC Fund, 3 deals together
- [Initialized Capital](https://shizune.co/investors/profile/initialized-capital) — VC Fund, 3 deals together
- [Lightspeed Venture Partners](https://shizune.co/investors/profile/lightspeed-venture-partners) — VC Fund, 3 deals together
- [Caffeinated Capital](https://shizune.co/investors/profile/caffeinated-capital) — VC Fund, 2 deals together
- [Fort Ventures](https://shizune.co/investors/profile/fort-ventures) — VC Fund, 2 deals together

## About Innerspace

VC Fund · San Francisco, United States

InnerSpace develops and distributes sensors that enables its users to create 3D maps of the area around them. The sensors can be used to create a range of applications, including wayfinding, marketing, and tracking apps. InnerSpace was founded in 2014 by Matt MacGillivray, Jason Gamblen, and James Wu and is based in Toronto.

2 contacts available at Innerspace.

| Name | Title | Profile |
| --- | --- | --- |
| Joe Greenstein | Co-Founder & Zookeeper's Assistant | https://shizune.co/investors/profile/joe-greenstein |
| Semira Rahemtulla | Cofounder & Director | https://shizune.co/investors/profile/semira-rahemtulla |

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## FAQ

### What does Joe Greenstein invest in?

Joe Greenstein invests primarily in Software, Mobile and Internet startups, most often at Seed and Series A stage. Most of the 24 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### What is Joe Greenstein's check size?

Joe Greenstein typically joins rounds of $465k–$5.5M at Seed, $650k–$2M at Pre-Seed and $1.2M–$14M at Series A. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Joe Greenstein participates in.

### When did Joe Greenstein last invest?

The most recent investment recorded for Joe Greenstein closed in Dec 2024. Shizune tracks 24 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.

### Is Shizune's investor data accurate?

Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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