Neuralink

OpenAI

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.

OpenAI

OpenAI makes money primarily through API access and subscriptions. The API charges developers per token (roughly per word) for using GPT models in their applications.

ChatGPT Plus costs $20/month for individual users, ChatGPT Team is $25-30/user/month, and ChatGPT Enterprise is custom-priced. Microsoft pays OpenAI licensing fees and also resells OpenAI models through Azure OpenAI Service.

OpenAI's annualised revenue ran past $13 billion during 2025 and kept climbing from there, which is the kind of growth curve that normally only exists in a pitch deck.

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.

OpenAI

OpenAI was founded in December 2015 as a nonprofit AI research lab. The founding donors — including Elon Musk, Sam Altman, Peter Thiel, Reid Hoffman, and Jessica Livingston — pledged $1 billion with a mission to build artificial general intelligence (AGI) that would benefit all of humanity.

The idea was that AI was too important and too dangerous to leave in the hands of Google alone.

Sam Altman became chairman while Greg Brockman (former CTO of Stripe) became president. Ilya Sutskever, one of the most respected AI researchers alive, left Google Brain to become chief scientist.

The early team was stacked with world-class researchers who published their work openly — hence "Open" AI.

But AI research turned out to be staggeringly expensive. Training large models required millions of dollars in compute.

In 2019, OpenAI created a "capped-profit" subsidiary — investors could earn up to 100x their money, but profits beyond that would flow to the nonprofit. Microsoft invested $1 billion.

The mission was still to save humanity. The method now involved making a lot of money first.

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.

OpenAI

ChatGPT's launch in November 2022 was the growth strategy — it just wasn't planned that way. The team expected a modest research preview.

Instead, ChatGPT hit 1 million users in 5 days and 100 million monthly active users in 2 months, making it the fastest-growing consumer application in history. The product went viral because it felt like magic — for the first time, anyone could have a natural conversation with a machine that seemed to understand them.

The Microsoft partnership provided distribution at massive scale. Microsoft integrated OpenAI models into Bing, Office 365 (Copilot), GitHub (Copilot), and Azure.

Overnight, hundreds of millions of Microsoft users had access to OpenAI technology. Microsoft's $13 billion investment was the largest AI bet in history and gave OpenAI nearly unlimited compute.

The API created an ecosystem. Thousands of startups built products on top of OpenAI's models — from customer service bots to coding assistants to content generators.

Each API customer locked themselves into OpenAI's ecosystem, creating switching costs and recurring revenue.

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.

OpenAI

The board crisis of November 2023 nearly destroyed the company. The nonprofit board fired Sam Altman as CEO on a Friday, citing a loss of confidence.

Within 48 hours, 95% of employees threatened to quit and follow Altman to Microsoft. By Tuesday, Altman was reinstated and the board was restructured.

The incident exposed the fundamental tension between OpenAI's nonprofit governance and its for-profit ambitions — a tension it finally addressed in late 2025 by restructuring the business as a public benefit corporation sitting under the original nonprofit.

The cost of training frontier models is eye-watering. Each new GPT generation costs hundreds of millions to train.

OpenAI is reportedly spending over $7 billion annually on compute. The company is burning through cash faster than almost any startup in history, which is why it keeps raising at higher and higher valuations.

If revenue growth slows before costs stabilize, the math gets ugly.

Safety concerns are not going away. Multiple prominent researchers have left OpenAI over disagreements about the pace of development versus safety research.

Ilya Sutskever, the chief scientist who was central to the board's decision to fire Altman, left in 2024 to start a safety-focused AI lab. The public debate about whether OpenAI is moving too fast — and whether its safety commitments are genuine — grows louder with every capability improvement.

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 64 flexible threads carrying 1,024 electrodes 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.

OpenAI

ChatGPT is the consumer chatbot — the product that made AI mainstream overnight. The flagship GPT models are multimodal, handling text, images, and audio in one system.

The OpenAI API lets developers integrate GPT into any application. DALL-E generates images from text descriptions.

Whisper transcribes and translates audio. Sora generates videos from text prompts.

GPT Store lets users create and share custom GPT agents. ChatGPT Enterprise gives businesses a private, secure version of ChatGPT with admin controls and no data training.

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.

OpenAI

Microsoft ($13B), Thrive Capital, Khosla Ventures, Sequoia Capital, Founders Fund, Tiger Global, SoftBank, a16z