Twitter Goes to War With Substack

Lon Harris
Lon Harris is a contributor to dot.LA. His work has also appeared on ScreenJunkies, RottenTomatoes and Inside Streaming.
Twitter Goes to War With Substack
Evan Xie

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Substack announced a new feature this week called “Notes,” which will allow users to publish brief posts containing a few sentences, quotes, simple reactions, images, and links. These Notes are going to get their own dedicated tab, separate from longer-form Substack content, and the basic format feels purposefully borrowed from Twitter. Individual notes can be liked, replied to, and reshared – just like tweets – and there will even be separated tabs for authors to which you’re specifically subscribed vs. content from your “extended Substack network,” similar to Twitter’s “Following” vs. “For You” structure.


In their blog post outlining the new feature, Substack co-founders Chris Best, Hamish McKenzie, and Jairaj Sethi were quick to differentiate Notes from Twitter, drawing attention specifically to their revenue model. While Twitter is free (unless you’ve just GOT TO have that blue check) and writers receive no direct financial compensation for their contributions, Substack remains subscription-based. Rather than aiming for virality for its own sake, Team Substack argues that subscriptions provide a genuine incentive for posting quality content, as Notes will help Substack authors convert “casual readers into paying subscribers.”

High-minded rhetoric aside, Substack could clearly use a hot new feature. According to newly-disclosed SEC statements, the company burned through around $25 million in cash during a major 2021 expansion, up from just $1 million in expenses the year before. For the entire year 2021, the company earned gross revenue of just $11.9 million, mostly from its share of blog subscriptions. (2022 data is currently unavailable.)

Despite the obvious aesthetic similarities between Notes and Twitter, and Substack’s very overt attempts to lure away Twitter users, they seem likely to remain different kinds of platforms. In large part because so much of the power of Twitter is in its wide-open accessibility to all. Though a small percentage of overall users drive most of Twitter’s activity and engagement, they’re not always the same people who could attract massive paid followings on a platform like Substack. It remains to be seen whether a subscription-based platform can drive conversations and generate the kinds of breakout viral moments that have made Twitter feel essential.

Nonetheless, Twitter seems to view Notes as a threat. Within 24 hours of the feature’s announcement, the social network and microblogging service began scaling back interactivity with Substack. At first, Substack writers were just unable to embed tweets in their posts, but now, Twitter has blocked all likes, retweets and comments on any links pointing back to a Substack newsletter. As well, Twitter users can’t link to a Substack blog via their profile, making it essentially impossible to use your Twitter account to promote a paid Substack blog. (At least for now, you can apparently still get around these changes with a URL shortener. But you didn’t hear that from us…)

Asked about the controversy by The Verge, Substack’s trio of founders used Twitter’s moves as further ammunition, pointing out that it’s dangerous for writers to rely on a platform on which “they don’t own their relationship with their audience” and “where the rules can change on a whim.”

Beyond just bolstering a key argument in favor of its competitor, Twitter’s decision to go to war with Substack pretty clearly makes its own platform worse. By removing the incentive of promoting work for which they actually get paid, it seems likely that this move will discourage some active users – who, again, drive the bulk of Twitter’s traffic and engagement – from tweeting as much. Tellingly, the Substack purge even removed some links to Matt Taibbi’s “Twitter Files” reporting, produced in coordination with Twitter and its owner, Elon Musk.

As well, Twitter’s prominence is largely based around being at the center of so much online conversation and discourse. By removing the ability of Substack writers to refer back to tweets, Twitter is purposefully taking itself out of a lot of these discussions. If you make it significantly harder for writers to talk about tweets… they might actually stop talking about tweets. Which would be far worse for Twitter, overall, than just the presence of a new competitor, which may not actually be a direct competitor anyway.

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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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          How Replify Found Its Niche and an Acquirer

          🔦 Spotlight

          Hello LA,

          This week’s startup story began three years ago with an AI assistant built for almost any small business. It ended, or perhaps graduated, with an acquisition by one of the fitness industry’s largest technology providers.

          ABC Fitness has acquired Replify, an AI platform that manages customer communication for gyms and wellness businesses across phone, text, email and chat. Its virtual agents can answer questions, qualify leads, schedule tours and classes, follow up on missed calls and run outbound campaigns. Financial terms were not disclosed.

          Before Replify found its footing in fitness, it was HeyLibby, a general-purpose AI assistant founded in 2023 by former Zillow colleagues Spencer Rascoff, Tony Small and Anna Rodriguez. The company was incubated inside Rascoff’s 75 & Sunny Labs and initially set out to help small businesses turn incoming messages into qualified leads.

          That broad vision gave HeyLibby a large potential customer base, from real estate agents and contractors to hairstylists and event planners. But as the team searched for product-market fit, one industry’s problem stood out. Gym and wellness employees were often too busy helping customers in person to answer every call, text or email, leaving prospective members waiting and potential revenue on the table.

          That insight reshaped the company. HeyLibby narrowed its focus to fitness and wellness, raised a $4.5M seed round in 2025 and later rebranded as Replify. It went on to work with brands including Gold’s Gym and UFC Gym, proving that its AI agents could do more than answer routine questions. According to the company, customers have captured up to 10 times more leads and shortened sales cycles from roughly 30 days to as little as three to five days.

          ABC Fitness became a natural next step. The company provides software to more than 30,000 fitness businesses serving over 40 million members worldwide. By adding Replify to its platform, ABC can offer gyms an always-available AI front desk while bringing Replify’s technology to a much larger global customer base.

          Replify’s journey offers a useful lesson amid the rush to build AI products for everyone. The company began with a broad promise, identified a customer with a specific and expensive problem, and built deeply around that need. Gym owners did not need another flashy chatbot. They needed someone to answer the phone when the front desk could not.

          Sometimes the smartest AI strategy is simply picking up the call.

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

          🤝 Venture Deals

            LA Companies

            • Dimension raised a $1.65M seed round backed by Science Inc., UpscaleX, OpenSky, Long Run Capital, 1864 Fund and others. The profitable social-commerce company will use the funding to launch Seller OS more broadly, an agentic AI platform that automates TikTok Shop operations for brands and agencies. - learn more
            • Procode raised a $10M Series A led by Health Velocity Capital, bringing its total funding to $14M. The AI-powered medical billing company will use the capital to acquire two additional billing businesses and expand its platform beyond plastic surgery and dermatology into all surgical specialties and ambulatory surgery centers. - learn more
            • Antares raised $470M in Series C financing, including $370M in equity and $100M in debt, in a round co-led by Paradigm and Caffeinated Capital. The nuclear energy company will use the capital to commercialize its autonomous microreactors, with an electricity-producing model planned for 2027 and initial deployments at U.S. military installations beginning in 2028. - learn more

            LA Venture Funds
            • Wilshire Lane Capital participated in Ellis’ more than $10M seed round, which was led by First Round Capital and included Kearny Jackson, 645 Ventures, Harlem Capital, Khosla Ventures and others. Founded by Cadre founder Ryan Williams, Ellis has emerged from stealth with an AI-native operations platform that helps private credit managers reconcile fragmented data and automate workflows such as portfolio monitoring, investor reporting and compliance; the funding will support team growth and further product development. - learn more
            • Rebel Fund participated in Dili’s $15M Series A, led by Khosla Ventures, bringing the AI compliance company’s total funding to $21.7M. Dili helps energy, construction, infrastructure and manufacturing companies identify compliance issues by reviewing project data in real time, and will use the funding to expand its team and broaden its platform into additional audit and waste-detection workflows. - learn more
            • B Capital led ChipAgents’ $60M Series A2, which brought the semiconductor AI startup’s expanded Series A financing to $134M. ChipAgents will use the funding to scale customer deployments, expand its engineering and go-to-market teams and further develop its AI platform, which automates complex chip design and verification workflows. - learn more
            • StoryHouse Ventures participated as a returning investor in Henry AI’s $16.5M Series A, led by FirstMark Capital with backing from Thomson Reuters Ventures, Y Combinator and others. The commercial real estate AI company will use the funding to expand its engineering and product teams and scale Henry Deal, a platform that automates underwriting, offering materials and other back-office work throughout a transaction. - learn more
            • Walkabout Ventures and Bungalow Capital co-led Discern’s $10M Series A, bringing the company’s total funding to $17.5M. Discern provides a software-based registered agent service that automates state filings and compliance tasks, and will use the capital to scale its platform following fourfold annual recurring revenue growth in 2025. - learn more
            • Starshot Capital participated in Quercus Biosolutions’ oversubscribed $5M seed round, which was led by Serra Ventures and included several climate, agriculture and grower-backed investors. The agtech startup will use the funding to expand its pipeline of AI-designed proteins for fighting herbicide-resistant weeds, begin regulatory work and explore applications targeting fungi, insects and other crop pests. - learn more
            • B Capital co-led Flourish Health’s $26M Series A alongside F-Prime and Cherryrock Capital, bringing the youth mental health provider’s total funding to $46M. Flourish will use the capital to expand its psychiatrist-led, in-home care model nationwide, hire and train clinicians and further develop its AI-enabled platform for coordinating care. - learn more
            • Powerhouse Capital participated in European Technology Network’s $1.6M seed round alongside Axel Springer, a LADbible co-founder and angel investors from OpenAI and DeepMind. The London-based tech media startup will use the funding to open a larger studio, expand its team, launch a newsletter and increase its livestreamed programming from two shows per week to five. - learn more

            LA Exits

            • Saltair, the Los Angeles body-care brand founded by model and entrepreneur Iskra Lawrence, is selling a majority stake to private equity firm TSG Consumer. Financial terms were not disclosed, but the deal will support Saltair’s expansion across e-commerce, retail and new products, while Lawrence transitions into the role of chief community advocate. - learn more
            • Digital marketing agency GR0 plans to acquire Ultimate AI’s enterprise deployment division and use the team’s technology to launch a new company called GR0 AI. The platform will deploy AI agents across brands’ customer data, commerce and marketing systems to personalize outreach, recover abandoned sales and generate measurable revenue; financial terms were not disclosed. - learn more

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