Ambercycle’s CEO on Why Traditional Recycling Won’t Work, and What His Technology Does Instead

Camay Abraham
Camay Abraham is a journalist, researcher, and a freelance reporter for dot.LA. She covers fashion, tech and culture and has previously written for Glossy, i-D, Dazed and Screen Shot, among other outlets. She has an MA in fashion psychology from London College of Fashion and has been interviewed by Vice and ABC Australia for her work in fashion and well-being. Pronouns: she/her.
Ambercycle’s CEO on Why Traditional Recycling Won’t Work, and What His Technology Does Instead

Few industries are as tangled with buzzwords as the fashion industry. Clothing brands, rightly concerned about their tremendous effects on the environment, are eager to call their collections “green” or “sustainable.” But making tangible changes in how clothing is produced and distributed has been a struggle.

On Tuesday, L.A.-based startup Ambercycle announced it raised a $21.6 million Series A round to try to tackle the problem. The funding comes from fashion heavyweights including H&M (which has used its technology in recent collections) and online fashion and shoe retailer Zalando, among others. It will go to ramping up production of the company’s fiber regenerative technology, which it created and piloted in a manufacturing plant downtown.


Ambercycle co-founders Shay Sethi and Moby Ahmed are scientists and former UC Davis college roommates. The two see themselves as different from traditional fashion or manufacturing founders – and other research-based innovators.

“Traditionally, people have always thought, ‘here's an interesting technology, how do we craft a story around it?’” Instead, Sethi says, Ambercycle “start[s] with the products that we would really like to see and then work backwards into the technology. We develop, do research and engineering that way instead of starting in the lab.”

Ambercycle CEO and co-founder Shay Sethi

Ambercycle CEO and co-founder Shay Sethi

Their technology is able to break down the components of clothing to its basic polyester materials, separating its natural fibers and dyes, and creating a new material in the process, which they call cycora.

“We imagined a technology that could take an old t-shirt and turn it back into the yarns required to make that green t-shirt again,” he adds. “Anything that's in your closet today – like yoga pants or dress shirts – that's traditionally made of polyester can be made with cycora.”

Sethi and Ahmed started their company in San Francisco in 2015, then moved it to Los Angeles’ garment district two years later, looking for a manufacturing hub close to a center of innovation.

“We felt like this is a really good nexus for innovation, fashion – as well as material sciences,” Sethi says. “There is a very strong industry and a very strong familiarity with manufacturing so we felt it was a perfect blend. Also we grew up in California and didn't want to leave.”

We chatted with Ambercycle co-founder Shay Sethi about his company’s journey, its new funding and how it plans to get beyond buzzwords in planning a sustainable future for fashion.

What are the biggest challenges to the fashion industry?

When we consider the future of humanity, there's a couple key things that need to change. The big one is – given that consumption will not decrease – the reliance on natural resources will put a strain on the way in which we can live on this planet. So in order to change that, we need to take advantage of these traditionally viewed as waste streams and turn them back into new resources. So the future upstream will be all of these textile materials that are in our closet. But it's not really easy today to throw away or recycle our old garments.

We need to be able to have a low-friction way to throw away our garments and have them go back into a circular system. If we can tell a transparent and traceable story to a person, then brands and retailers will start to care.

Why is it so hard to recycle clothing currently?

So let's talk about our clothing. They are mixtures of different fibers – polyester and cotton, as well as dyes, additives, zippers, tags and stains – when they're at their end of life. We can't really recycle those materials, because they're these complex, intimate blends. Recycling has really struggled as a business, and also as a solution to waste, because you can't create a high quality product from those materials once they are at their end of life.

How is Ambercycle different from other recycling processes?

Most recycling processes are shredding or very simple mechanical processes. You can turn a t-shirt into pillow stuffing in a similar way that you can turn paper into a sort of grey newspaper and then downcycle it; The same thing happens with textiles.

The Holy Grail is really being able to turn an old t-shirt into a new t-shirt. So over the past five years, we’ve developed technology that takes these mixtures of materials that have dyes and additives, put them through a process, and make the base raw materials needed to make those same yarns. This goes in line with what's traditionally known today as circular economy where you can reuse materials, again and again.

Will Ambercycle always be focused on apparel?

Right now our focus is on apparel.

We have a couple of luxury clients that are really interested in transitioning to circular systems. Over the next couple of years, we're going to be able to talk about those, but the major message we want to help shed light on is that every year, over 120 billion garments go to landfill. We need to, as a fashion industry, transition to a circular system. It's [not] just one or two companies that can do things; Everyone as a whole needs to adopt a new ecosystem, where things are being reused in supply chains over and over again. It's very important for this transition to involve all verticals in the power supply chain. The demand for these materials is already so high. So people already care. I think we're just trying to figure out the logistics of the society right now.

There's a lot of possibilities when you think about it. You can imagine this being transformed into a system that can take other materials as well. I think we're excited about the possibilities in the future but I’m really focused on the textile-to-textile stories today.

What do you plan to do with your recent funding?

We’re trying to scale up the number of projects we're doing with different companies across the apparel industry that will require a lot of manpower or womanpower. That's a key gap we need to fill. A technology like ours that uses sort of molecular separation technologies, that advanced material science requires a sort of scale before you can really start to see the fulfillment of these contracts.

It's very easy to make a couple of t-shirts, but it's very hard to make millions and millions and millions of kilograms of stuff. We're going to be scaling up production of one of our main materials today, cycora. Demands are already way through the roof. I felt like right now was the right time to raise external capital to accelerate that plan.

This interview was edited for clarity and brevity.

This Torrance Startup Just Raised $1B to Mass-Produce Hypersonic Missiles

🔦 Spotlight

Happy Friday, Los Angeles.

Castelion has spent the past four years trying to prove that hypersonic missiles do not need to take decades to develop or cost so much that the military can only afford a limited supply.

Now comes the harder part: producing them at scale.

The Torrance-based defense startup raised a $1B Series C at a $13B valuation. The financing includes $800M in equity and a $250M revolving credit facility, making it one of the largest recent raises for an LA defense technology company.

JPMorganChase’s Strategic Investment Group, Andreessen Horowitz and Carlyle co-led the round. Lightspeed Venture Partners, Lavrock Ventures, Altimeter, General Catalyst, T. Rowe Price and LA-based Interlagos Capital also participated.

Castelion will use the capital to ramp production of Blackbeard, its low-cost hypersonic strike missile, while developing a longer-range precision weapon and new defensive systems. Hundreds of millions of dollars will go toward expanding manufacturing at Project Ranger, the company’s 1,000-acre production campus in New Mexico.

Image Source: Castelion

Blackbeard was designed in California, will be built in New Mexico and is expected to enter service in 2027. Castelion says it has already secured more than $500M in U.S. military contracts over the past 18 months and moved the missile from a clean-sheet concept to an official program in fewer than four years.

That timeline is central to Castelion’s pitch. Traditional defense programs are often associated with long development cycles, limited production runs and eye-watering costs. Castelion is applying the rapid testing and vertically integrated manufacturing approach popularized by commercial space companies to weapons production.

But a $13B valuation changes the standard. Castelion is no longer being judged as a promising startup with an impressive prototype. It is being funded like a company expected to become a major part of the American defense industrial base.

The question is no longer whether a startup can build a hypersonic missile. It is whether one can manufacture thousands of them without losing the speed, discipline and cost advantages that made it disruptive in the first place.

For LA’s defense ecosystem, that shift matters. The region has become home to a growing number of companies promising to modernize how America builds critical hardware. Castelion now has the capital, contracts and facilities to show what happens when that promise reaches the factory floor.

The next test will not be in a pitch deck. It will be in production.

More from this week’s LA startup and venture scene below.

🤝 Venture Deals

    LA Companies

    • Long Beach based Ampaire raised a $19M Series B led by DiamondStream Partners, with strategic participation from Alaska Star Ventures and IAGi Ventures, bringing its total funding to $68M. The hybrid-electric aviation company will use the capital to expand flight operations, produce additional Eco Caravan aircraft, advance regulatory certification and scale its manufacturing capabilities. - learn more

    LA Venture Funds
    • SUM Ventures participated in AssistMe’s €6.5M funding round, which was led by CRB Health Tech and Vorwerk Ventures and included several returning investors. The German care technology company will use the capital to expand across Europe, prepare for a U.S. launch and further develop alea, its digital platform for supporting caregivers and improving nursing-home operations. - learn more
    • CIV led Hypercubic’s $5.3M seed round, with participation from Y Combinator, Afore Capital, Pioneer Fund, Multimodal Ventures and several angel investors. The San Francisco startup will use the capital to develop AI agents that can analyze, document and rewrite decades-old COBOL systems, helping enterprises modernize critical mainframe software faster and with less risk. - learn more
    • Plus Capital participated in Wispr Flow’s $280M Series B, led by Menlo Ventures and joined by existing and new investors, valuing the AI voice company at $2B. The funding brings Wispr’s total capital raised to $361M and will support its expansion beyond dictation into meeting tools and proprietary speech technology, including its new Canto model. - learn more
    • Alexandria Venture Investments participated in Leal Therapeutics’ $30M Series A extension alongside new investor Eli Lilly and returning backers including OrbiMed, Newpath Partners and SV Health Investors’ Dementia Discovery Fund. The biotech company will use the funding to advance clinical trials of LTX-001 for schizophrenia and LTX-002 for ALS, with initial schizophrenia trial data expected by year-end. - learn more
    • BroadLight Capital participated in Higgsfield’s $400M Series B, led by DST Global and joined by investors including Goldman Sachs Alternatives, Smash Capital, Fifth Wall and Intel Capital. The AI video and image platform, now valued at $5.4B with $700M in annualized revenue, will use the funding for R&D, global infrastructure, AI hiring and international expansion. - learn more

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      Why Samsonite Just Paid $178.5M for BÉIS

      🔦 Spotlight

      Hello, Hello.

      This week, one of LA’s most recognizable consumer brands packed its biggest bag yet.

      Samsonite Group has agreed to acquire an 85% stake in BÉIS for $178.5M, valuing the Los Angeles-based travel and lifestyle brand at approximately $210M. The deal is expected to close in Q4, pending regulatory approval.

      Founded by actress and entrepreneur Shay Mitchell and incubated by LA-based Beach House Group in 2018, BÉIS has grown from a digitally native luggage startup into a profitable business that generated approximately $210M in sales last year. Along the way, it built the kind of fiercely loyal online following that legacy brands spend years and considerable marketing budgets trying to manufacture.

      Image Source: BÉIS

      That may be the most interesting part of this deal. Samsonite is not simply acquiring another luggage line. It is buying access to a younger, predominantly female customer base, a sophisticated direct-to-consumer operation and a brand that knows how to turn social media attention into actual sales. The suitcases are useful; the cultural relevance is the real carry-on.

      BÉIS will continue operating as a standalone brand under CEO Adeela Hussain Johnson and its existing management team. Mitchell will retain a 15% ownership stake and continue guiding the company’s creative and product vision, while Samsonite brings the global distribution, sourcing and logistics infrastructure needed to take the brand further.

      For LA’s startup community, the acquisition is another reminder that valuable technology companies do not always look like software companies. BÉIS built its advantage through digital distribution, community and an unusually sharp understanding of its customer. Now, one of the world’s largest luggage companies wants what it created.

      Sometimes the strongest exit starts with knowing exactly what people want to pack.

      More from this week’s LA startup and venture scene below.

      🤝 Venture Deals

        LA Companies

        • Heaviside Industries raised a $60M Series B to accelerate the development and production of its autonomous precision munitions for U.S. and allied forces. The company also announced a strategic partnership with defense manufacturer Nammo, combining Heaviside’s autonomous weapons technology with Nammo’s expertise in propulsion, warheads and large-scale munitions production. - learn more
        • Alex Cooper and Matt Kaplan’s media company Unwell received its first outside investment from WTSL, giving the profitable business a $500M pre-money valuation. Unwell, which reaches a reported 70M women each month through podcasts, film and television, live events, consumer products and a creative agency, will use the capital to pursue acquisitions, make investments and expand into new business lines. - learn more
        • Neros raised a $250M Series C at a $2.5B valuation, with participation from LA-based Interlagos, MANTIS Venture Capital and Thiel Capital. The El Segundo defense startup will use the funding to scale its autonomous strike and interceptor drone programs, expand production and strengthen its domestic supply chain as demand grows from the U.S. military and allied forces. - learn more
        • FriskAI raised $3.6M from MaC Venture Capital to expand its observability and security platform for AI agents. The startup helps companies monitor what autonomous agents do in real time, giving teams greater visibility into agent behavior and helping them identify errors, risks and unexpected actions. - learn more
        • Diald raised $1M in follow-on funding led by Feedback Ventures, bringing its total funding to $4.75M. The company also launched a rebuilt conversational AI platform that lets commercial real estate investors create pro formas and evaluate zoning, permits, neighborhood sentiment and other property risks through plain-language prompts. - learn more

        LA Venture Funds
        • Alexandria Venture Investments participated in Khartis Therapeutics’ $50M Series B, led by Forge Life Science Partners, bringing the San Diego biotech’s total funding to $95M. Khartis will use the capital to advance its lead oral treatment for thyroid eye disease and expand its pipeline of small-molecule immunology drugs. - learn more
        • Finality Capital Partners co-led Entravel Group’s $7.5M funding round alongside Ethereal Ventures, with participation from GSR, Varrock, G1 Ventures, Seier Capital, Veris Ventures, Funfair Ventures and WTG Ventures. The traveltech company will use the capital to expand its white-label hotel-booking infrastructure beyond crypto platforms and develop a stablecoin-powered system for settlement, treasury and working-capital financing. - learn more
        • Regeneration.VC participated in Clarity Systems’ $4.4M seed round, led by LMnT Ventures and joined by Humba Ventures and Massive Technology Ventures. Clarity uses X-ray imaging, computer vision and AI to detect counterfeits, product swaps and other forms of returns fraud in seconds without opening the package. - learn more
        • CIV participated in AGent Energy’s $11M Series Seed round alongside existing investor Zero Infinity Partners, with Spero Ventures and MassMutual Ventures co-leading and Intrepid Investment Management also joining. The Houston startup uses AI-powered hardware and software to turn largely idle backup generators into on-demand grid capacity during emergencies, and the new funding brings its total raised to $17M. - learn more
        • Smash Capital co-led CodeRabbit’s $143M Series C alongside Atomico, valuing the AI code-review company at $1.5B. CodeRabbit will use the funding to expand internationally and develop its new Agentic Change Management platform, which helps companies review, govern and monitor software created by both humans and AI agents. - learn more
        • Multiball Capital backed Soctera’s $4M seed round alongside Anorak Ventures, with additional participation from 9Yards Capital, Mana Ventures and Red Bear Ventures. The Cornell spinout will use the funding to develop heat-efficient power amplifiers designed to improve the range, signal quality and reliability of radar, electronic warfare, satellite and telecommunications systems. - learn more
        • WndrCo participated in Genera’s $10M seed round, which was led by First Round Capital and also included BoxGroup, Carpenter Capital and Success Venture Partners. Genera will use the funding to scale its AI platform, which automates the often labor-intensive process of deploying enterprise software, including customer discovery, data migration and system configuration. - learn more
        • M13 co-led Baselayer’s $20M Series A alongside Koro Capital, bringing the fintech startup’s total funding to approximately $47M. Baselayer will use the capital to enhance its AI-powered platform, which helps banks, fintech companies and government agencies automate business verification, risk assessment and fraud monitoring. - learn more

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          Two LA Startups Raised $2.37B to Build What AI Needs

          🔦 Spotlight

          Happy Friday, LA.

          The largest checks in tech are increasingly going toward companies trying to build their way out of America’s biggest physical constraints.

          This week, two Los Angeles startups raised a combined $2.37 billion in equity to tackle two particularly urgent ones: how the country manufactures critical hardware and where it will find enough electricity to power the AI era.

          Torrance-based Hadrian is building highly automated factories for defense and aerospace. El Segundo’s Valar Atomics wants to manufacture nuclear reactors at scale. Different industries, same underlying bet: the next generation of technology will depend on our ability to produce physical infrastructure much faster than we do today.

          Hadrian raised $1.37 billion in Series D funding, bringing its valuation to $7.87 billion. The company plans to use the capital to open new factories, expand research and development, and increase its capacity to produce critical defense, aerospace and industrial systems.

          Hadrian’s pitch is straightforward, if wildly ambitious: America needs to relearn how to build things and build them quickly.

          Its factories combine skilled workers with AI, robotics and proprietary software to manufacture precision components and, increasingly, complete mission-critical systems. Its customers include defense giants such as Lockheed Martin and RTX, along with newer players like Anduril.

          The company has come a long way from simply making aerospace parts. Hadrian is positioning itself as a piece of America’s industrial infrastructure, offering manufacturers a way to rapidly scale domestic production at a time when wars abroad, strained supply chains and growing defense demands have made the country’s manufacturing gaps increasingly difficult to ignore.

          Investors are clearly buying the argument. The new round comes just over a year after Hadrian raised $260 million, suggesting that “reindustrialization” has officially graduated from venture capital buzzword to billion-dollar investment thesis.

          Meanwhile, roughly 15 miles away in El Segundo, Valar Atomics is moving even faster than its enormous ambitions suggested.

          When we last wrote about Valar, the company was reportedly raising $450 million at a $2 billion valuation and racing to prove that nuclear energy could move on AI’s timetable. Now, it has closed a $1 billion Series B led by Sequoia Capital, secured an additional $200 million credit facility and reportedly reached a $6 billion valuation.

          Valar is developing standardized, factory-built nuclear power plants designed to avoid the enormous costs and decades-long construction timelines associated with traditional nuclear projects. Its goal is not merely to build a working reactor, but to eventually manufacture fleets of them.

          That ambition also sounds considerably less theoretical than it did when we first covered the company. In June, Valar’s Ward 250 reactor achieved a self-sustaining nuclear reaction. Just one week later, the company demonstrated the reactor generating electricity to power an Nvidia Blackwell system. Valar now says the new funding will help it move from proving its technology works to producing reactors at scale.

          The timing is no coincidence. AI’s enormous appetite for electricity is forcing the tech industry to confront a basic reality: the cloud still has to plug into something. Training models and operating massive data centers will require far more reliable power, and nuclear energy is rapidly becoming one of Silicon Valley’s favorite answers.

          Hadrian and Valar may be solving different problems, but their unusually large rounds point to the same shift. AI can design, predict and automate, but it cannot manufacture a missile component or generate a megawatt of electricity on its own. That requires factories, energy systems, supply chains and a great deal of capital.

          For years, venture-backed companies competed to build the software layer. Now, some of the biggest bets are being placed on the infrastructure underneath it.

          The future may run on AI. But first, someone has to build what keeps it running.

          More from this week’s LA startup and venture scene below.

          🤝 Venture Deals

            LA Companies

            • Endeavor Optical Networks emerged from stealth with $10.75M in seed funding from General Catalyst and Andreessen Horowitz to develop a satellite network that uses lasers to move data between continents. The startup plans to use the capital to build an optics lab, hire engineers and conduct ground testing ahead of a demonstration satellite launch targeted for late 2027. - learn more
            • Actualyze AI emerged from stealth with a $7M seed round backed by Storm Ventures, Canaan Partners, Morado Ventures and AME Cloud Ventures. Its platform gives enterprises a central control layer for managing AI usage across teams and applications, helping them enforce security policies, track spending, route requests between models and maintain audit trails. - learn more
            • Blaze.tech raised $8.5M in pre-seed funding led by Friale, a healthcare-focused venture firm founded by the family behind HCA Healthcare. The company helps digital health startups, providers and payers turn AI-generated prototypes into HIPAA-compliant software for uses including e-prescribing, EHR integrations, telehealth and auditing. - learn more

            LA Venture Funds
            • Canon Capital participated in Oligo Security’s $60M funding round alongside Ballistic Ventures, Greenfield Partners, Lightspeed Venture Partners, Red Dot Capital Partners, TLV Partners and other investors, bringing the cybersecurity company’s total funding to $140M. Oligo will use the capital to accelerate product development and expand its global go-to-market operations as it helps organizations detect and block software exploits in real time. - learn more
            • Matter Venture Partners participated in Volta’s seed and Series A financing alongside Azora, Andreessen Horowitz, Altimeter, NVIDIA and Michael Dell’s family office, valuing the AI infrastructure startup at $2.4B. Emerging from stealth, Volta plans to use the backing to develop and operate large-scale AI data centers, supported by a $5B infrastructure financing program with Azora and a $10B European compute partnership. - learn more
            • Cedars-Sinai participated in Cirrus Therapeutics’ expanded seed financing through its Intellectual Property Company, bringing the ocular immunology biotech’s total funding to $14.7M. Cirrus will use the backing to advance its gene and cell therapy pipeline, including a lead treatment for geographic atrophy, while a new collaboration with Singapore Eye Research Institute and Duke-NUS will support research, clinical development and expansion across Asia-Pacific. - learn more
            • Strong Ventures made a follow-on investment in Ready Robust Machine’s ₩13.4B Series B, which was led by Quantum Ventures Korea and brought the heavy-equipment technology company’s total funding to ₩22.9B. The company develops energy-recovery systems for hydraulic machinery and will use the capital to build out mass production, expand its data services and enter the Japanese market. - learn more

            LA Exits

            • Artium has been acquired by global consulting firm AlixPartners, bringing its expertise in building enterprise-grade AI agents for clients including BNY Mellon, Mayo Clinic and eBay to a broader global platform. The company will continue operating as a distinct team under the name Artium by AlixPartners, retaining its founders, employees, methodology and research relationships. - learn more

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