tony

Maroon Lake Capital

[Matt Loszak @MattLoszak]

Very excited to announce that at 12:20am on the 4th of July, Aalo achieved criticality on our first full-scale reactor.

We cut it close, but we pulled it off!!

Working towards this goal with such an incredible group of humans has been the most fulfilling period of my life. This moment has been three years in the making.

Last year, Executive Order 14301 called for at least three new reactors to go critical before July 4th, 2026.

As of late last Friday night, that goal has been surpassed!

When the EO was announced, we immediately sat down to figure out what the most ambitious scope would be, while still being potentially achievable by July 4th.

Some of the team proposed doing simplified designs with smaller fuel loads, or building in existing facilities.

One thing was clear: We wouldn't have time to integrate a full-scale sodium heat-removal loop to bring the reactor to its full 30 MWt.

So here’s where we landed:

➡️ We purchased the entire commercial-scale fuel load. This is enough fuel to operate at 30 MWt / 10 MWe for 3 years before refueling. To my knowledge, it’s the largest fuel load that’s been taken critical in the DOE pilot program, by far.

➡️ We built a full-scale reactor vessel in our factory, and loaded in our commercial graphite layout. All the dimensions, vessel thickness, and manufacturing techniques are essentially the same as we will use for the imminent commercial version. There will be a few minor tweaks for sodium flow and full-power, but nothing major.

➡️ We built an entirely new reactor facility at the Idaho National Lab. Building a building is easy. Building a new reactor facility comes with a mountain of paperwork, policies, operation and training procedures, security, instrumentation and control, and more.

Zero-power criticality might seem like a small step, but I can tell you, going through the exercise of building a reactor and taking it to criticality has been extremely valuable.

The learnings on regulatory, ops, manufacturing, supply chain, QA, economics, engineering, and design will accelerate our path through to the final iteration at full-power.

America is blessed to have a recent Cambrian explosion of startups in nuclear, all going after different markets, technologies, and strategies.

I’m excited that sodium, gas, salt, and new PWRs are all getting pushed forward once again. The best outcome for humanity is to have all these advance in parallel, as quickly as possible, while maintaining safety.

Thanks again to our amazing team, DOE, INL, BEA, and everyone else who helped us get to where we are today.

This could not have happened anywhere else. Happy birthday, America!! 🇺🇸🇺🇸🇺🇸

There has never been a better time for nuclear energy. The Second Atomic Age has begun, and this one will be here to stay.

[delian @zebulgar]

This is what I voted for

🇺🇸🇺🇸🇺🇸

[Marc Andreessen 🇺🇸 @pmarca]

USA. 🇺🇸

[Max Hodak @maxhodak_]

we're taking this flag to the stars

[Gavin Baker @GavinSBaker]

Retail, Substack, Reddit and most of all @X accounts are increasingly the most important forces in the stock market and yet there is no way for them to connect directly with the management teams of the companies they are writing about and investing in. And they have almost no visibility into the late-stage private companies that are ever more important.

The @TomorrowXSummit aims to change this. Hosted by @antoniogracias and Valor Equity Partners, @iconnections_io and @rbiscardi and @atreidesmgmt, we are going to have our own version of the superb Morgan Stanley or Goldman Sachs TMT conference with an epic line-up of both public and private companies. Instead of having sell-side analysts interview management teams, we are going to have X accounts like @citrini and buysiders do the fireside chats. We expect thousands of  attendees at the Moody Center in Austin, November 17-18 and please note that security will be extremely tight given some of the CEOs that are going to speak.

Attendance will be free for X accounts that contribute positively to the discourse and affordable for retail accounts. Happy that this means friends like @DanielSLoeb1 , @altcap ,  @plaffont , @patrick_oshag and the @theallinpod crew will be able to afford the price of admittance should their schedules permit. And perhaps we can even get them on a panel or have them interview some management teams. I am sad to say there will be a different price for institutional investors who are not on X unless they are willing to reveal their anonymous handle, but I think this is going to be awesome for all. And everything will eventually be posted here on X for all to see. Open source for the win.

Link to the website to sign up in the next post:

[Afshine Emrani MD FACC @afshineemrani]

I'm a cardiologist. I've spent twenty years as the person patients trust to interpret their bodies. And I need to tell you something that most physicians won't say out loud:

AI is about to change the power dynamic between you and your doctor. Forever.

Four days ago, OpenAI's o3 model diagnosed 18 children with rare diseases that the best human specialists at Boston Children's Hospital couldn't solve — some after nearly twenty years of searching. Published in the New England Journal of Medicine.

Two weeks ago, WashU researchers proved that nine routine blood markers can calculate your biological age — and predict cancer risk years before any tumor forms. A free calculator. Available to anyone.

Last month, AI-enhanced coronary CT angiography detected inflamed arteries in patients whose standard stress tests said "normal." Patients who would have gone home reassured and wrong.
The pattern is unmistakable. The tools that used to require a specialist, a referral, a three-month wait, and a $400 copay are migrating into your phone, your bloodwork portal, and your own hands.

And I'm watching something in my practice I never expected.
Patients are walking in more informed than some of the residents I trained. They've run their PhenoAge score. They know their ApoB. They've read the study about Lp(a) before I've had time to bring it up. They come with questions so specific that the conversation starts at a level it took me years of training to reach.
This used to threaten physicians. It shouldn't. It should liberate us.
Because here's the truth about the old model: a 15-minute appointment where your doctor runs a basic metabolic panel, glances at the numbers, says "looks fine," and sends you home — that model was never good enough. It was just all we had. It missed 75% of future heart attacks. It caught cancer late. It told women with microvascular disease they had anxiety. It filed children with rare diseases as "unsolvable."

AI doesn't replace the physician. I've said this before and I mean it — the human moment, the clinical judgment, the hand on the shoulder when the diagnosis lands — that's irreplaceable.

But AI does something the old model never could: it gives you the ability to see inside your own biology with a depth and speed that was impossible a decade ago. To track your own numbers. To calculate your own biological age. To bring data to your doctor that elevates the conversation from "am I sick?" to "where exactly am I heading, and what do we do about it?"

The patient who walks in with their ApoB, their Lp(a), their hsCRP, their PhenoAge calculation, and a list of questions from the latest research — that patient doesn't threaten me.

That patient is the easiest person in my practice to keep alive.
Because they've already done the one thing most patients never do: they stopped waiting for permission to understand their own body.

I went into medicine because I wanted to help people live longer. What I've learned is that the patients who live longest are the ones who took ownership — not of my job, but of their own data, their own questions, and their own decisions.

The tools are here. The research is published. The calculators are free. The blood tests cost less than a dinner out.

You don't need to wait for your annual physical to find out what's happening inside you. You don't need permission to understand your own biology. And you don't need to accept "looks fine" from anyone — including me — when the science offers a deeper answer.

The revolution isn't coming. It's in your pocket. In your patient portal. In the published studies you can read yourself.

The only question left is whether you'll use it — or keep waiting for someone to tell you it's time.
Your body. Your data. Your life.

Take ownership. Your future self is counting on it.

[Shaun Maguire @shaunmmaguire]

Most of @sequoia went on a hardware trek to LA this week

We visited

@reflectorbital

@Nominal_io

@Mach_Industries

@neros_tech (we got a drone show; last photo)

@K2SpaceCo

@VardaSpace

@GoToImpulse

(And more)

The ecosystem is buzzing

HARDWARE IS BACK, baby 🚀

[Jaya Gupta @JayaGup10]

https://t.co/5vDrndcmFn

[Rivet @RivetTax]

Teams getting compliant faster with Rivet:

Crosby
Cursor
Ramp
Physical Intelligence
Cognition
Rox
Coder
ModRetro
Modal
Unify
AdQuick
Chai Discovery

and many more

[Amy Deng @amydeng_]

I’m an AI researcher turned brain tumor patient, and recently I used the models to crack my mystery fatigue faster than my PCP could.
I believe everyone can do the same with their own symptoms. Here’s how:

[homans top guy @passcoderonald]

Gaethje absorbing the Faustian Spirit from the deceleration of independence before beating the breaks off Topuria as a +350 underdog is just further proof this nation has a mandate from heaven

[Loofy @Loofyb0i]

SpaceX is filing for an IPO at $2T. Anthropic and a dozen AI companies are right behind it.

Thomas Laffont at Coatue explains why this is not 1999. The "10x Paradox": models get 10x better, prices drop 10x, demand explodes 100x.

33-min and you'll understand the power law that determines who wins in AI

bookmark - it's the most important investment framework for the next 3 years

[Matan Grinberg @matanSF]

https://t.co/OGzWHkbs1R

[Matt Turck @mattturck]

A day in the life of a VC in 2026:

9am: Board meeting. My main value-add is aggressively pushing for Anthropic/OpenAI usage in non-engineering functions. Briefly ponder how I became an SDR for foundation model companies.

1pm: Lunch with another VC. We discuss how startups can find "blue ocean" away Anthropic/OpenAI. We conclude we should probably just invest the rest of our funds directly into Anthropic/OpenAI.

3pm: Pitch meeting. Me: "Do you run on Anthropic or OpenAI?" Founder: "Both." Debating internally whether a company reselling Anthropic/OpenAI with a 10% gross margin is a good investment but hey, at least they're in the "token flow".

4:30pm: Deep due diligence. I ask Claude if it plans to build this exact startup natively in its next release. Same to ChatGPT. They both say yes. I pass on the deal.

6pm: Urgent call from a portco CTO: "We need an intro to upgrade our Anthropic tier!" I immediately agree to help them spend more of the venture dollars we just invested in them, on Anthropic.

8pm: Brainstorming next guests for the podcast. Thinking I should probably just try to get some folks from Anthropic and OpenAI.

[Siddharth @siddharthvader_]

https://t.co/1bTGqbhbP2

[tony @toni_MLC]

@DoveyWanCN @vast 姐 varda投不

[CuiMao @CuiMao]

各位好，这真的是我最后一个关于Anthropic的故事了，本视频由seedance2制作完成。感谢你一直以来对我的关注。结尾有彩蛋。

[Zach Dell @ZachBDell]

Extremely excited to share this one.

We recently signed a 40 MW deal with @austinenergy to deploy our distributed storage technology here in Austin.

More to come in the coming weeks on our offering for homeowners in Austin.

Very proud to partner with our hometown utility.

[SpaceX @SpaceX]

Fram2’s Mission Commander @satofishi is set to fly aboard Starship’s first interplanetary human spaceflight mission → https://t.co/7ehxZJSGXd