# MCJ: portfolio, investments and team

> MCJ is a vc firm based in United States. 47 investments on record, 16 in the last 12 months, latest Sept 2026. Portfolio, stages, co-investors and team.

Source: https://millionrounds.com/fund/mcj (Millionrounds; every figure on the page links to its filing or article)

United States · [Investor](https://millionrounds.com/investors)

# MCJ

Last cheque observed Sep 2026; 47 cheques on record.

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Deploying now New fund $68M, Jan 2024 VC firm

Seed Series A Energy Climate Industrial

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Deploying now

**94%** of best year **16** **cheques in 12 months**, 47 on record

Since the last cheque **60** days **00** hrs **00** min **00** sec

Median round **$9.0M** Rounds led **0 of 47** Sole investor **1 rounds** Mostly in **United States, 83%**

Pitch MCJ

## MCJ highlights

- 01 16 cheques in the last 12 months
- 02 Mostly Seed and Venture: 60% of its rounds
- 03 Sole investor in 1 rounds, median $2.0M

## What they do

> We back founders rewriting industries for the future. From their own website

- **Type:** VC firm
- **Cheque size:** Not stated
- **Stages:** Seed Series A
- **Sectors:** Energy Climate Industrial
- **Based in:** Boston, United States
- **Cold pitches:** Not stated

## The record

Every round we can evidence, newest first **47 appearances**

- **2026** 14 rounds
- **Sept** **[Odyssey](https://millionrounds.com/company/odyssey)** Debt · US **$47M** With 4 others
- **Sept** **[Light](https://millionrounds.com/company/light)** Series A · US · TechStartups **$46M** With 11 others
- **Aug** **[Reservoir](https://millionrounds.com/company/reservoir)** Seed · US · TechCrunch **$8.0M** With 2 others
- **Jul** **[Clean Crop Technologies](https://millionrounds.com/company/clean-crop-technologies)** Venture · US **$7.9M** With 2 others
- **Jul** **[Rodatherm Energy](https://millionrounds.com/company/rodatherm-energy)** Grant · US **$8.0M** With 2 others
- **Jun** **[Red Metals](https://millionrounds.com/company/red-metals)** Seed · US · Ventureburn **$10M** With 3 others
- **Jun** **[Verse](https://millionrounds.com/company/verse)** Series B · US **$54M** With 4 others
- **May** **[Moment Energy](https://millionrounds.com/company/moment-energy)** Series B · CA **$3.0M** With 2 others
- **May** **[Recheck](https://millionrounds.com/company/recheck)** Pre-seed · US **$2.0M** Sole investor
- **Apr** **[Clarasight](https://millionrounds.com/company/clarasight)** Series A · US **$12M** With 6 others
- **Apr** **[Impossible Metals](https://millionrounds.com/company/impossible-metals)** Venture · US **Undisclosed** With 3 others
- **Feb** **[DG Matrix](https://millionrounds.com/company/dg-matrix)** Series A · US · TechCrunch **$60M** With 8 others
- **Feb** **[Archimetis](https://millionrounds.com/company/archimetis)** Venture · US **$12M** With 2 others
- **Jan** **[Sensesemi](https://millionrounds.com/company/sensesemi)** Seed · US **$2.7M** With 2 others
- **2025** 8 rounds
- **Dec** **[Unlimited Industries](https://millionrounds.com/company/unlimited-industries)** Seed · US **$12M** With 4 others
- **Nov** **[Overstory](https://millionrounds.com/company/overstory)** Series B · NL · Blume Equity **$43M** With 11 others
- **Oct** **[Kodama Systems](https://millionrounds.com/company/kodama-systems)** Seed · US **$7.0M** With 4 others
- **Aug** **[Aalo Atomics](https://millionrounds.com/company/aalo-atomics)** Series B · US · TechCrunch **$100M** With 15 others
- **Jul** **[LGND](https://millionrounds.com/company/lgnd)** Seed · US **$9.0M** With 3 others
- **May** **[Rhizome](https://millionrounds.com/company/rhizome)** Seed · US **$6.5M** With 2 others
- **Apr** **[Fourier](https://millionrounds.com/company/fourier)** Series A · US **$19M** With 1 other
- **Jan** **[Moment Energy](https://millionrounds.com/company/moment-energy)** Series A · CA · Audacy **$15M** With 9 others
- **2024** 9 rounds
- **Dec** **[Artyc PBC](https://millionrounds.com/company/artyc-pbc)** Venture · US **Undisclosed** With 4 others
- **Oct** **[Energetic Capital](https://millionrounds.com/company/energetic-capital)** Venture · US **Undisclosed** With 4 others
- **Oct** **[AirLoom Energy](https://millionrounds.com/company/airloom-energy)** Seed · US **$7.5M** With 3 others
- **Sept** **[Mantel](https://millionrounds.com/company/mantel)** Series A · US **$30M** With 2 others
- **Jul** **[Paces](https://millionrounds.com/company/paces)** Series A · US **$11M** With 6 others
- **Jun** **[Waterplan](https://millionrounds.com/company/waterplan)** Grant · US **$150K** With 4 others
- **Feb** **[Lilac Solutions](https://millionrounds.com/company/lilac-solutions)** Series C · US **$145M** With 4 others
- **Feb** **[Arch](https://millionrounds.com/company/arch)** Seed · US **$6.2M** With 2 others
- **Feb** **[Cirplus](https://millionrounds.com/company/cirplus)** Venture · DE **Undisclosed** With 4 others
- **2023** 6 rounds
- **Oct** **[Yard Stick](https://millionrounds.com/company/yard-stick)** Venture · US **Undisclosed** With 4 others
- **Sept** **[Opna](https://millionrounds.com/company/opna)** Seed · GB **$6.5M** With 4 others
- **Apr** **[Phuc Labs](https://millionrounds.com/company/phuc-labs)** Venture · US **Undisclosed** With 2 others
- **Apr** **[Evergrow](https://millionrounds.com/company/evergrow)** Seed · US **$7.0M** With 4 others
- **Apr** **[Helio](https://millionrounds.com/company/helio)** Seed · GB **$3.3M** With 6 others
- **Mar** **[Lun](https://millionrounds.com/company/lun)** Seed · DK **$11M** With 4 others
- **2022** 6 rounds
- **Sept** **[Kopperfield](https://millionrounds.com/company/kopperfield)** Seed · US **$5.0M** With 4 others
- **Sept** **[Cloud to Street](https://millionrounds.com/company/cloud-to-street)** Series A · US **$12M** With 3 others
- **Jun** **[Rheaply](https://millionrounds.com/company/rheaply)** Venture · US **$20M** With 5 others

An announcement gives the size of the round, not the size of this investor's cheque: the only rounds that imply a cheque are those where they were the sole named investor.

## The team

Named by the firm itself, on a filing, its Form ADV or its company registration **5 named**

DB **David B Aronoff** Managing Member of the General Partner i Filing they signed

JJ **Jason Jacobs** Managing Member of the General Partner i Filing they signed

JC **Justin Cody Simms** Managing Member of the General Partner i Filing they signed

TN **Thai Nguyen** Managing Member of the General Partner i Filing they signed

YL **Yin Lu** Managing Member of the General Partner i Filing they signed

We also hold **6** people at this firm from the lists this database was built from: a weaker source than the filings, since a list does not say when a title ended. Login to see them.

## What the register says

From the firm's own filings with the SEC, which it must file accurately by law

**$85M** gross assets of its funds Oct 2026

**Exempt** reporting adviser venture or small private funds

- **Legal name:** MCJ Management, L.P.
- **SEC number:** CRD 310880

## What they claim to have backed

From their own portfolio page (on their website)

**0** of 2 we have independently watched raise

Events ↗ Mcj

Weaker than a round we watched, stronger than a list somebody sold us. A firm is far less willing to put a company on its own site that it never funded.

New fund on file

**$68M**

raised in Jan 2024

From its SEC filing, not a journalist: a firm that has just raised has money to deploy.

## The cheque

Seed Series A

Median round joined **$9.0M** the round, not its cheque Alone, median **$2.0M**

Led 0 of 47 rounds **0%**

- **Sole investor:** 1 rounds
- **Last cheque:** Sept 2026

Rounds by stage said on their site

- Seed said *17*
- Venture *10*
- Series A said *10*
- Series B *4*
- Grant *2*
- Pre-seed *2*

Cheques by month Led Joined

Nov 2023 Oct 2026

Often in the room with

- [Lowercarbon Capital](https://millionrounds.com/fund/lowercarbon-capital) 8
- [Liquid 2 Ventures](https://millionrounds.com/fund/liquid-2-ventures) 5
- [Powerhouse Ventures](https://millionrounds.com/fund/powerhouse-ventures-limited) 5
- [Techstars](https://millionrounds.com/fund/techstars) 5
- [Alumni Ventures](https://millionrounds.com/fund/us-strategic-tech-fund-an-alumni-ventures-fund) 4
- [Climate Capital](https://millionrounds.com/fund/climate-capital) 4

**Pitching MCJ?** Put them on your fundraising board with this record on the card, and follow them to hear when they write a new cheque.

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## Who they invest alongside

The investors most often in the same rounds as MCJ. A count of rooms they were both in, not a relationship either has claimed.

[**Lowercarbon Capital** VC firm **8** rounds together](https://millionrounds.com/fund/lowercarbon-capital)[**Liquid 2 Ventures** VC firm **5** rounds together](https://millionrounds.com/fund/liquid-2-ventures)[**Powerhouse Ventures** VC firm **5** rounds together](https://millionrounds.com/fund/powerhouse-ventures-limited)[**Techstars** VC firm **5** rounds together](https://millionrounds.com/fund/techstars)[**Alumni Ventures** VC firm **4** rounds together](https://millionrounds.com/fund/us-strategic-tech-fund-an-alumni-ventures-fund)[**Climate Capital** VC firm **4** rounds together](https://millionrounds.com/fund/climate-capital)[**Andreessen Horowitz** VC firm **3** rounds together](https://millionrounds.com/fund/andreessen-horowitz)[**Breakthrough Energy** VC firm **3** rounds together](https://millionrounds.com/fund/breakthrough-energy)[**Coatue** VC firm **3** rounds together](https://millionrounds.com/fund/coatue-management)[**Congruent Ventures** VC firm **3** rounds together](https://millionrounds.com/fund/congruent-ventures)[**Engine Ventures** VC firm **3** rounds together](https://millionrounds.com/fund/engine-ventures)[**Pale blue dot** VC firm **3** rounds together](https://millionrounds.com/fund/pale-blue-dot)

## Recently backed

The latest companies MCJ put money into.

[**Odyssey** $47M · Sept 2026](https://millionrounds.com/company/odyssey)[**Light** $46M · Sept 2026](https://millionrounds.com/company/light)[**Reservoir** $8.0M · Aug 2026](https://millionrounds.com/company/reservoir)[**Red Metals** $10M · Jun 2026](https://millionrounds.com/company/red-metals)[**Moment Energy** $3.0M · May 2026](https://millionrounds.com/company/moment-energy)[**Recheck** $2.0M · May 2026](https://millionrounds.com/company/recheck)

## Quick answers about MCJ

### What does MCJ invest in?

MCJ invests most often at Seed and Venture (60% of the rounds on record), in sectors such as Energy, Climate and Industrial.

### How active is MCJ?

47 investments on record, 16 of them in the last 12 months. The most recent was in Sept 2026.

### What has MCJ invested in recently?

Its most recent investments on record: Odyssey (Debt, Sept 2026), Light (Series A, Sept 2026) and Reservoir (Seed, Aug 2026).

### How big are MCJ's cheques?

The median round it joins is $9.0M.

### Does MCJ lead rounds?

Rarely, if at all: none of its 47 investments on record names it as the lead.

### Where does MCJ invest?

Most of the companies it backs are in the United States (83%), Canada (5%) and the United Kingdom (5%).

### Is MCJ investing now?

Yes: it is actively investing, with 16 investments in the last 12 months.

### Who does MCJ invest alongside?

Most often Lowercarbon Capital (8 rounds together), Liquid 2 Ventures (5 rounds together) and Powerhouse Ventures (5 rounds together).

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