Sam Altman

Altman is a prolific early-stage investor who backs deep tech and moonshot ideas. His portfolio through YC and personal investments includes hundreds of companies.

His personal bets tend toward civilizational-scale technology — nuclear fusion, longevity research, AI safety. He has said he thinks the most important investments of the next decade will be in energy and AI.

He has repeatedly said he holds no equity in OpenAI itself, which is unusual for a founder running a company of that size and something he has been asked about constantly.

Bill Nygren

Classic large-cap value. Nygren buys businesses trading significantly below his estimate of intrinsic value — typically at least a 40% discount.

He focuses on companies with strong management teams, high free cash flow generation, and the ability to allocate capital intelligently. He runs concentrated portfolios (20-30 stocks) and is willing to hold positions for 3-5+ years.

He is a contrarian by default — his best ideas are usually in sectors the market hates.

Sam Altman

Altman believes we are approaching AGI — artificial general intelligence — and that it will be the most transformative and potentially dangerous technology humans have ever built. He thinks the right response is to build it carefully rather than cede the frontier to those who might not.

He argues that the returns from AI will be so large they will need to be distributed broadly to prevent catastrophic inequality. He has floated ideas around universal basic income funded by AI productivity.

Bill Nygren

Nygren believes the market is generally efficient but occasionally misprices individual businesses, especially during periods of fear or sector-wide pessimism. He thinks like a business buyer, not a stock trader — asking "what would a rational private buyer pay for this entire company?" He considers management quality and skill at investing company money as important as the financial statements.

Sam Altman

Altman has said that playing it safe at this moment in history is the most dangerous thing he could do. His belief: AGI is coming whether OpenAI builds it or not — the only question is who builds it and with what values.

That conviction makes conventional risk aversion feel irresponsible to him. He holds large personal positions in nuclear fusion companies and longevity biotech — bets that could return 1000x or go to zero.

He has said that any genuinely interesting bet carries existential downside risk. That is what makes it interesting, not a reason to avoid it.

Bill Nygren

Moderate. Nygren runs concentrated portfolios which adds stock-specific risk, but he focuses on large-cap, established businesses with strong balance sheets.

He is not swinging at biotech startups or crypto. The risk is being early and looking wrong for extended periods while waiting for the market to recognize value.

Sam Altman

He has written about sleeping 8 hours, exercise, not scheduling meetings before 11am, eating the same lunch every day, and blocking large chunks of uninterrupted time for thinking. He is a known prepper — he has said he owns land, gold, guns, and antibiotics in case civilization collapses, which is a mildly alarming admission from the CEO of the company building AGI.

Bill Nygren

Low-profile lifestyle. Based in Chicago.

Nygren does not seek media attention and rarely appears on financial TV. He writes detailed quarterly commentaries for Oakmark shareholders that are some of the best free investing education available.

He lets his long-term performance record speak for itself.

Sam Altman

OpenAI and ChatGPT. The launch of ChatGPT in November 2022 was the most consequential product launch in tech in at least a decade.

It brought AI from a niche technical field into mainstream awareness overnight and made OpenAI the fastest-growing AI company in history. Altman navigated the transition from nonprofit to commercial entity, secured $13 billion from Microsoft, and built a company valued at $157 billion within five years.

Bill Nygren

His consistency over nearly three decades. While many value managers have stumbled during the growth-dominated 2010s, Nygren adapted his approach to include "modern value" — companies like Alphabet and Meta that trade at low multiples relative to their growth rates.

His willingness to evolve his definition of value without abandoning the discipline has kept Oakmark relevant.

Sam Altman

Being fired by his own board in November 2023 — and the board's subsequent reversal. Whatever actually happened in those five days is still murky.

What is clear is that the board lost control of the situation the moment it became obvious that without Altman, most of the company would leave. The board members who voted to fire him are gone.

Altman is back with more power. The episode revealed real governance problems at one of the most consequential companies in history.

Bill Nygren

Holding financial stocks through the 2008 financial crisis. Oakmark Fund was down significantly in 2008 as bank and insurance stocks cratered.

While the long-term recovery proved him right on many of those holdings, the drawdown was painful for investors who redeemed at the bottom.

Sam Altman

Sam Altman dropped out of Stanford in 2005 to co-found Loopt, a location-sharing startup. Loopt was acquired in 2012 for $43 million — not a huge exit but enough to establish him as a serious founder.

He then became president of Y Combinator in 2014, succeeding Paul Graham. Under Altman, YC expanded from a small cohort model to a much larger operation with global reach, including backing Airbnb, Dropbox, Stripe, and hundreds of others in its portfolio.

In 2019, he stepped down from YC to become CEO of OpenAI. The company launched ChatGPT in November 2022, which became the fastest-growing consumer application in history — 100 million users in two months.

In November 2023, the board fired him. The entire company revolted.

Microsoft — OpenAI's biggest investor — nearly hired him to run a new AI division. Five days later, he was reinstated with a restructured board.

OpenAI's valuation hit $157 billion in 2024 and roughly $852 billion by 2026.

Bill Nygren

Joined Harris Associates (parent of Oakmark Funds) in 1983. Became lead portfolio manager of the Oakmark Fund in 2000.

Lead manager of Oakmark Select Fund since 1996 and Oakmark Global Select since 2006. Oakmark Select Fund has returned over 11% annually since 1996 inception.

Manages over $20 billion across Oakmark strategies. Named Morningstar Domestic Stock Fund Manager of the Year in 2001.

Known for buying out-of-favor large-cap value stocks and holding them for years. Has consistently argued that the market overreacts to short-term problems and undervalues franchises with durable competitive advantages.

Sam Altman

OpenAI (CEO). Y Combinator (former president).

Loopt (co-founder, acquired 2012). Personal investments through Hydrazine Capital and a long list of early-stage bets.

Notable: Stripe, Helion Energy (nuclear fusion, where he is also chairman and the largest investor), and Retro Biosciences (longevity), which he seeded with $180 million of his own money.

Bill Nygren

Oakmark Funds (lead portfolio manager), Harris Associates (partner)

Sam Altman

Stanford University — studied computer science. Dropped out in 2005 after his sophomore year to found Loopt.

Bill Nygren

CFA charterholder. MBA from the University of Wisconsin-Madison.

Undergraduate degree from the University of Minnesota. Has spent his entire career at Harris Associates — over 40 years at one firm.