Bargain Hunting in the Series B Aisle, Lab-Grown Guts, and Fresh Intel from Nearly 70 Angel Groups

Happy Thursday.

In today’s issue:

• Angel Deals of the Week

• One epic bookmark

• The best nugget from my conversation with John Harbison, ACA Board Member, Chairman Emeritus of TCA Venture Group, and co-author of the 2025 Angel Funders Report.

  • PSA: Today’s “nugget” is a combination of my takeways from chatting with John + some light analysis of the AFR. Buckle up.

• Exclusive opportunity for angel network leaders

🔥 Angel Deals of the Week

Angel funding rounds announced in recent weeks, compiled from public sources. These deals represent the elite few that survived an angel network’s vetting process. Note: I have not personally analyzed these companies and am sharing for informational purposes only.

🤖 Deal summaries generated using dealmemo.ai.

🧾 Check out every deal we’ve tracked here.

Swirltex Inc. | Wastewater membrane treatment tech

Participating Group: Central Texas Angel Network (CTAN)

Swirltex develops proprietary membrane technology that transforms wastewater into reusable resources, reducing energy consumption by over 60% compared to conventional treatment systems. The company serves food & beverage, produced water, industrial retrofits, and municipal wastewater markets through decentralized modular units that deliver higher throughput at lower operational costs. Swirltex secured $1.2 million in follow-on funding from Central Texas Angel Network to expand operations serving customers across broader climate ranges where conventional membranes fail.

Peter Christou | Calgary, Canada | August 2025 | Source

YEEO Eco-Safe | Sustainable mosquito control tech

Participating Group: New Mexico Angels

YEEO Eco-Safe develops yeast-encapsulated essential oil technology for mosquito control, targeting a market where mosquito-borne diseases affect 700 million people annually. The company's patented solution achieves nearly 100% mosquito larvae elimination within 24 hours using non-toxic materials. YEEO recently closed a seed round and received $250,000 from the New Mexico Economic Development Department, with backing from New Mexico Angels. The company is pursuing EPA approval while establishing test sites across the U.S. and exploring Southeast Asian markets.

Kevin Pope | Albuquerque, NM | July 2025 | Source

Intero Biosystems | Lab-grown organs for drug testing

Participating Group: Houston Angel Network

Intero Biosystems creates miniature lab-grown human gut organs for pharmaceutical companies to test new drugs. Their GastroScreen platform grows complete "intestines in a dish" with all the key tissues found in the human digestive system, allowing drug companies to test safety and effectiveness without using animals. The company recently closed an oversubscribed $2 million pre-seed round with participation from members of the Houston Angel Network to increase production and develop disease models for pharmaceutical partnerships. The University of Michigan spinout has recently won major startup competitions and is capitalizing on growing industry demand for alternatives to animal testing, supported by FDA and NIH endorsements.

Charlie Childs, Ph.D. | $2M Pre-Seed | Ann Arbor, MI | June 2025 | Source

📣 Have an Angel Deal to Announce?

🔖 Bookmarks

I’m breaking the mold (mould?) on bookmarks this week.

There is ONE resource that is 100% worth your time.

It’s called the Angel Funders Report, from the Angel Capital Association. This report dropped on Friday and breaks down angel activity across the US (almost 70 angel groups contributed this year) and it’s just fantastic.

P.S. You might be thinking “wow Andrew sure is excited about this thing, I wonder if he’s getting paid for this.” Nope - it’s just great and I think you will be glad you made the time to skim it.

🥇 The Nugget: My Top Takeaway from This Week’s Conversation with John Harbison + Light Analysis from the Angel Funders Report

Don’t Auto-Decline Later-stage Angel Deals 🙅‍♂️🙅‍♂️

Pre-Seed is Expensive. Series A/B is Cheap.

PSA: Today’s “nugget” is a combination of my takeways from chatting with John + some light analysis of the AFR. Buckle up.

The recent valuation compression between very-early-stage and sort-of-early stage funding rounds is blowing my mind. To me, this was the most striking chart from the entire AFR.

Notice that in 2021, the gap between Pre-Seed rounds and Series B rounds was $28M. Last year, that reduced to a mere $9M.

Wow.

This suggests that, all else being equal, an investor could pay $10M for pre-seed/seed risk OR they could pay less than 2x for Series B risk.

Unsurprisingly, this compression is matched by a jump from 2023-2024 in the ratio of follow-on vs initial fundings across reporting angel groups, where for the first time since 2020 follow-ons (52%) outpaced initial fundings (48%).

Ok but… why?

I have 3 theories:

1. Early early stage is just frothy. It feels like everybody does pre-seed / seed now, driving up valuations and making it more natural for founders to negotiate higher prices. Doubling from $5M pre-seed to $10M avg in one year is wild.

2. Increasing reliance on / acceptance of convertible instruments is artificially inflating the pre-seed/seed data. Page 42 of the report highlights that 37% of deals were done on convertibles (SAFEs and Convertible Promissory Notes), the highest percentage on record. My understanding is these median valuation trends are based on priced rounds only. So if founders otherwise expecting lower valuations increasingly stick with convertibles to avoid locking in unfavorable terms, then only founders confident they can secure high valuations choose to price their rounds. This selection bias would skew the priced round dataset upward, making the median valuations appear more inflated than the broader market reality.

3. Are angels increasingly relegated to less competitive Series B deals? According to page 16, angel participation in Series B+ has dropped from 27% (2019) to just 17% (2024). I’m speculating a bit, but perhaps as later-stage rounds grow larger and more institutional, angels are only able to win allocations in Series B rounds with lighter competition for cap table space. This market segmentation could drive down the median valuations we observe in angel-accessible deals while “premium” Series B rounds get snapped up by VCs at higher prices and bigger checkbooks.

Takeaway: Many angels I interact with immediately toss out Series A and B stuff.

Don’t.

Ask yourself: “Would I rather buy maximum risk at $10M or dramatically reduced risk at $19M?” Reserve follow-on capacity into your investment strategy and ping portfolio companies for follow-on opportunities.

Want more? Check out my full conversation with John 👇

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The Angel Network Curator is LIVE: hit the button below to learn more, including how to sign up to get amplified exposure as a Featured Partner.

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Until Next Week 👋

Thanks for reading - have a great week.

-Andrew

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