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This wasn't your usual S-1 filing.

Most are drab financial documents: revenue, liabilities, risk factors. Line after line. Page after page.

Anthropic did something different. It wrote its own Good Book, BI's Henry Chandonnet writes.

Anthropic's S-1 reads less like an IPO filing with the SEC than a dispatch from a heavenly mountaintop: the gospel according to Claude.

• An age of miracles? Check.
• A statement of good and evil? Naturally.
• A noble mission, mentioned 79 times? Amen.

Seeking salvation for humanity and a blockbuster stock-market listing. Both, apparently, can fit on the same form.

The language suggests Anthropic isn't merely asking investors to believe it can make money. It asks them to believe in a mission grand enough to make its enormous AI spending look like a necessary cost.

That is the story Anthropic will soon take to Wall Street. At a potential $1.5 trillion to $2 trillion valuation, Anthropic could become the largest IPO ever — just as investors fret that an already wobbly AI trade may struggle to absorb another colossus.

Beneath the biblical flourishes, the filing also answers one of the biggest questions hanging over the AI boom, BI's Alistair Barr writes: Can AI labs actually make money? Yes, and potentially lots of it.

It is a remarkable document. Lucky for you, we've read its 300-plus pages and 259,031 words. Here are the key revelations.

The congregation is not quite of one mind.

Some investors see astonishing growth. Others see hundreds of billions of dollars in future compute commitments. See what smart people are saying about Anthropic's IPO paperwork.

Every doctrine needs an early believer. For Anthropic, that was Spark Capital. The firm appears more than 50 times in the S-1 because partner Yasmin Razavi sits on Anthropic's board; Spark led the company's $450 million Series C at a then-eye-watering $4.5 billion valuation in 2023.

That early faith looks set to be well-rewarded. Anthropic's seven cofounders are also poised to become extraordinarily wealthy when the company goes public. We're talking tens of billions of dollars.

In the next few weeks, public investors will finally get their chance to buy a piece of Anthropic, too.

But they should be aware: Anthropic wants public money, not much public input. Its founders will have 50.1% of the voting power, while a trust created and funded by the company has the ability to appoint four of its seven directors.

Inside the company, meanwhile, there is life among the believers. Anthropic's own workforce offers a glimpse of how Claude is reshaping the company from within, as it rapidly grows headcount and tries to build a "low-ego" culture.

And finally, a question worthy of theological debate: Did AI help write its own scripture? Business Insider put Anthropic's filing through an AI-writing detector. Here's what we found.

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The great window-shade debate

Airplane question for you: If you're in a window seat, do you keep the shade up or down?

We raised this in our morning news meeting a few days ago, and the room erupted into a fierce debate over flying etiquette. This is up there with whether reclining your seat is appropriate, or society's unwritten rules around airplane armrests or taking off your shoes and socks.

For some travelers, open shades offer a lot of positives. You can watch the clouds, take a photo, or just feel a little less claustrophobic at 35,000 feet. (I'm shades up, for sure!)

For others, leaving the shade open is an act of selfishness. Sunlight pouring into the airplane cabin can keep half the plane awake, or cause glare on laptop or tablet screens. These folks very much want the shades closed. Flyers have been intensely litigating the issue on Reddit in recent days.

So, who's right in the window-seat debate?

The practical answer depends on the moment. Many airlines require the shades to be open during takeoff and landing for safety reasons, so passengers and crew can spot hazards outside and emergency responders can see into the cabin. But once the plane reaches cruising altitude, there are generally few rules governing the shade.

From there, it's all etiquette.

We spoke with a former flight attendant who spent nearly a decade working for an international airline. She has particularly strong feelings about how this debate should be settled.

Where do you stand on the issue? Should airplane window shades be open or shut during flights? Drop me a note at srussolillo@businessinsider.com and let me know what you think.

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Leaning out

It was day two of my stay-at-home PTO. This is the time off that isn't for traveling or relaxing, but — as I told my group chat — to be a housewife.

And over three days, I was productive: I decluttered a closet, replaced a broken appliance, and even enjoyed a Pilates class at 11 a.m. Not only did I accomplish goals that had gotten dusty on my to-do list, but I also noticed other positive benefits. I listened more to my children and felt more present.

As an executive, I immediately wanted to repeat this: three days at the start of every quarter to simply be a housewife.

It's just one solution for what so many millennial women and mothers are trying to figure out as they climb the corporate ladder. While some are experimenting with balance, like me, others are simply leaning out altogether.

Business Insider's Julia Pugachevsky spoke to women in corporate America who, instead of continuing to aspire to the highest rungs of their organizations, became skeptical that they'd have the flexibility needed to do it all. So, they're leaning out.

It's what Trisha Daab, who had spent 20 years in corporate leadership roles, did. She took a year off. "I had no idea how tired I was until I stopped working," she said.

During that time, Daab volunteered at a food bank, tap danced, traveled, and spent more time with her children. She eventually decided she couldn't go back to the status quo. "Stepping away helped me realize my priorities had shifted," the 47-year-old said.

Former Meta COO Sheryl Sandberg, who coined the term "Lean In" to encourage women to pursue corporate leadership even when family obligations felt like another hurdle, told Business Insider that she understands why women are leaning out.

"This is not the women who are saying, 'I don't want to do it,'" Sandberg, 57, said. "It's the women saying, 'I don't want to do it because I'm not wanted, I'm not getting the same opportunities and the same support, and I face an unfair burden at home.'"

Sandberg said it's a shame because women leaders often advocate for policies that benefit women, such as egg freezing, lactation rooms, and competitive parental leave options.

"I just hope that enough women want those senior leadership roles," she added, "that we get the environment for women that they deserve."

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The problem of AI's impact on mathematicians is proving difficult to solve.

OpenAI solving a historically difficult math problem last month kicked off a wider debate about the role AI should play in mathematics.

Sam Altman tried throwing cold water on the AI-arithmeticians beef this week. He said mathematicians have largely gone from anger to acceptance about AI usage in the field.

But that sentiment doesn't quite track with some big names in the field who remain cautious about using the tech.

Terence Tao, a UCLA professor and math prodigy, isn't necessarily pessimistic about AI but also said the "romantic era" of math is over.

"We are entering an era where exciting new things are possible, but some things are being lost," he added.

AI's rapid disruption of mathematics is noticeable.

Shortly after publishing its solution to the Navier-Stokes equations, OpenAI solved an additional 700-plus math problems and released the data on GitHub.

NYU Math professor Tristan Buckmaster said OpenAI's solutions dump wiped out entire research programs.

Finding middle ground between the two sides is proving tricky.

The reaction to a student-run Caltech AI math event shows how seriously some mathematicians take the threat.

Caiman Moreno-Earle, a math major at Caltech, told BI's Truman Dickerson that seeing AI companies quickly solve these legendary math problems was "demoralizing."

It's why the 19-year-old decided to hold a "mathathon" where participants could use AI. Moreno-Earle even got Anthropic and OpenAI to each donate $1 million worth of computing power.

Then came the critics.

A letter garnering more than 700 signatories said the event "is likely to have destructive impacts for the mathematical community."

OpenAI eventually pulled out, but the event is still set to happen. Moreno-Earle maintains the mathathon was less about causing a stir and more about ensuring humans have a place in the field of mathematics in the AI era.

Some will argue mathematicians need to adapt to the times and newer tools. There was no point fighting to use a slide rule once the calculator arrived.

The way AI is going about upending the field is also ruffling feathers, though. AI's solutions aren't always clean or clear, requiring mathematicians to go back and verify its work.

And there are also questions about how AI is coming up with these solutions. Since some mathematicians brainstorm with AI models, some have speculated they're using their own work to front-run them to a solution.