Neuralink

Stripe

Neuralink

Neuralink doesn't have a traditional revenue model yet — it's still in clinical trials. The near-term plan is medical devices sold to hospitals and clinics for treating neurological conditions.

Brain-computer interfaces for paralysis, ALS, blindness, and other conditions would be reimbursed by insurance and healthcare systems, similar to cochlear implants or deep brain stimulators.

The long-term vision is consumer neurotechnology — healthy people choosing to get brain implants for enhanced cognition, communication, or AI interaction. This is years or decades away and faces massive regulatory and ethical hurdles.

But if it works, the total addressable market is literally every human brain on the planet.

The surgical robot is potentially a separate revenue stream. Even if the implant itself doesn't dominate, the precision robotics technology developed for neural surgery could be licensed to other medical device companies.

Neuralink has also built custom chip fabrication capabilities that could have applications beyond brain interfaces.

Stripe

Stripe charges a flat 2.9% + $0.30 per transaction. That's it.

No setup fees, no monthly fees, no hidden charges. The simplicity is the product.

When a customer pays on a website using Stripe, Stripe handles everything — fraud detection, currency conversion, bank transfers, tax calculation, compliance. The merchant just sees money arrive in their account.

On top of the core payments, Stripe has built an entire financial infrastructure stack. Billing for subscriptions, Connect for marketplace payments, Atlas for incorporating a company, Issuing for creating virtual cards, Treasury for banking-as-a-service, and Radar for fraud prevention.

They're basically building the financial plumbing for the entire internet.

Neuralink

Elon Musk had been talking about brain-computer interfaces publicly since at least 2016. His stated motivation was existential: if AI becomes superintelligent, humans need a way to merge with it or risk becoming irrelevant.

The solution, in his mind, was a direct neural link between the human brain and computers.

Neuralink was quietly incorporated in July 2016 in California. Musk recruited a team of eight co-founders — neuroscientists, engineers, and chip designers from institutions like UC Berkeley, MIT, and Lawrence Livermore National Laboratory.

The founding team included Ben Rapoport, a neurosurgeon who understood both the medical and engineering sides, and Dongjin Seo, who had done PhD research on neural dust (tiny wireless brain sensors).

The company operated in stealth for two years before a 2019 presentation where Musk revealed the vision: a coin-sized device implanted in the skull containing thousands of ultra-thin electrode threads inserted into the brain by a custom-built surgical robot. The threads are thinner than a human hair — roughly 5 microns wide — and each one contains multiple electrodes that read neural signals.

The robot was necessary because no human surgeon could place threads that thin without damaging brain tissue.

Stripe

Patrick Collison was 19. His brother John was 17.

They had already built and sold a company — Auctomatic, an eBay auction tool — for $5 million while still teenagers in Limerick, Ireland. Patrick went to MIT, John went to Harvard, and they both dropped out because they had a better idea.

The idea was embarrassingly obvious in hindsight. In 2010, accepting payments on the internet was a nightmare.

You had to get a merchant account, negotiate with a payment processor, deal with a gateway provider, handle PCI compliance, and write thousands of lines of code. It took weeks or months.

The Collisons thought it should take five minutes.

They built a simple API — seven lines of code — that let any developer start accepting credit card payments immediately. No merchant account.

No paperwork. No phone calls with banks.

Just paste seven lines of code and you're in business. They originally called it /dev/payments, then changed it to Stripe in 2011.

Peter Thiel and Elon Musk — the PayPal mafia — were among the first investors. Sequoia and Andreessen Horowitz piled in soon after.

The Collisons had built exactly what every developer on Earth had been wishing for.

Neuralink

Neuralink's growth strategy is the classic Musk playbook: start with the premium use case that justifies the cost, then scale down. Phase 1 is medical — treat severe neurological conditions where no other option exists.

Quadriplegia, ALS, locked-in syndrome. Patients who literally cannot move or speak are willing to undergo experimental brain surgery.

The FDA granted Breakthrough Device designation in 2020, and the first human trial (PRIME study) began in 2024.

Phase 2 is expanding medical indications — blindness, depression, epilepsy, Parkinson's. Each new condition multiplies the patient population and the regulatory pathway, building clinical evidence along the way.

Phase 3 — the moonshot — is consumer enhancement. Musk has described this as "conceptual telepathy," where you think a message and it sends.

This phase requires proving extraordinary safety over years of medical use first. Nobody is going to electively implant a brain chip unless the medical version has been proven safe for a decade.

Stripe

Stripe grew almost entirely through developer love. They didn't hire a sales team for years.

They didn't run ads. They just built the best developer documentation anyone had ever seen and let word of mouth do the rest.

The developer-first strategy was deliberate. The Collisons realized that in a startup, the developer usually decides which payment provider to use.

If you make the developer happy, you win the company. Stripe's API documentation became legendary — clear, beautiful, with working code examples in every language.

They also grew by growing with their customers. Early Stripe customers included tiny startups that later became giants — Lyft, DoorDash, Instacart, Shopify.

As those companies scaled to billions in revenue, Stripe's processing volume scaled with them. Stripe didn't need to acquire new customers because its existing ones kept getting bigger.

The international expansion was methodical. Instead of launching everywhere at once like Uber, Stripe carefully added country after country, making sure each one worked perfectly with local payment methods, currencies, and regulations.

By 2024 they were processing payments in 195 countries.

Neuralink

The FDA and regulatory approval process is the primary bottleneck. Brain implants are Class III medical devices — the highest risk category.

Every design change, every new indication, requires extensive clinical data. The USDA also investigated Neuralink in 2022 for potential animal welfare violations in their primate testing program, which created PR headaches.

Long-term biocompatibility is an unsolved problem. The brain treats any foreign object as an invader and forms scar tissue around it, which can degrade signal quality over time.

Making an implant that works reliably for decades inside a hostile biological environment is one of the hardest engineering problems in medicine. Neuralink's thread retraction issue in their first human patient — where some threads pulled away from the brain — highlighted how much work remains.

Talent retention has been rocky. Max Hodak, the original president, left in 2021.

Several founding scientists departed. Working for Musk is notoriously demanding, and the timeline pressure on a medical device company clashes with the inherent need for cautious, methodical development.

Stripe

Valuation whiplash. In 2021, Stripe hit a peak valuation of $95 billion during the fintech boom.

By 2023, they had to mark it down to $50 billion during the tech correction — a 47% drop that made headlines everywhere. Employees who had been paper millionaires suddenly weren't.

The valuation has since recovered to $91 billion after a secondary share sale in 2025, but those two years were rough for morale.

Competition is relentless. Adyen, the Dutch payments company, has been eating into Stripe's enterprise market.

Square (now Block) competes on the small business side. PayPal is everywhere.

New fintech players pop up constantly. The payments business has razor-thin margins and everyone is fighting for the same 2.9%.

Going public is the elephant in the room. Stripe has been expected to IPO for years.

Investors, employees, and the media keep asking when. The Collisons have consistently said they're in no rush, but with $8.7 billion raised and thousands of employees holding stock options, the pressure to provide liquidity is enormous.

As of 2025, they've opted for secondary sales instead of a public offering.

Neuralink

The N1 Implant — a coin-sized device (23mm diameter, 8mm thick) implanted flush with the skull containing a custom chip that wirelessly transmits neural data to external devices via Bluetooth. The R1 Robot — a precision surgical system that inserts 1,024 electrode threads into the brain with micron-level accuracy, avoiding blood vessels using computer vision.

The N1 User App — software that translates neural signals into computer commands, allowing users to control cursors, keyboards, and eventually robotic limbs through thought alone. BCI Software Platform — the signal processing and machine learning stack that decodes raw brain signals into intended actions.

Stripe

Stripe Payments is the core — accept credit cards, debit cards, Apple Pay, Google Pay, and 135+ payment methods in 195 countries. Stripe Connect lets marketplaces and platforms pay out to sellers (Shopify, Lyft, DoorDash all use it).

Stripe Billing handles subscription and recurring billing. Stripe Atlas lets you incorporate a US company from anywhere in the world — fill out a form, get a Delaware C-corp, bank account, and tax ID in days.

Stripe Radar uses machine learning to block fraud in real time. Stripe Treasury lets platforms offer banking services to their customers.

Stripe Tax automatically calculates and collects sales tax in every jurisdiction.

Neuralink

Elon Musk has been the primary funder, investing hundreds of millions of his personal wealth. The company raised $205 million in a Series C in 2021, then $280 million in a Series D in 2023 led by Founders Fund (Peter Thiel's firm).

A 2024 round reportedly valued the company at $8.9 billion. Google Ventures (GV) and DFJ Growth have also participated.

The investor base is narrow compared to most startups at this valuation.

Stripe

Peter Thiel, Elon Musk, Sequoia Capital, Andreessen Horowitz, General Catalyst, Founders Fund, Tiger Global, GV (Google Ventures), Goldman Sachs, Baillie Gifford