Bill Ackman

Ackman is a concentrated, long-hold, activist investor. He typically owns 5–10 positions at a time — sometimes fewer.

Each one involves exhaustive research. If he's buying, he has usually already built a 100-slide deck explaining exactly what's wrong with the company and exactly what needs to change to fix it.

His style is the opposite of index investing. He wants a controlling voice at the table.

He wants to talk to the CEO. He wants the board to change.

That's the "activist" part — he's not just buying a stock and hoping it goes up. He's buying it with a plan to force the thing that will make it go up.

The strategy works until it doesn't. When the thesis is right, he wins massively.

When the thesis is wrong and he's also very public about it, the losses are spectacular.

Bill Gates

Gates invests through Cascade Investment LLC in established, cash-generative businesses — railroads, waste management, agricultural equipment, farmland. His biggest single Cascade holding for years was Canadian National Railway.

He has sold most of his Microsoft stock over time. His investment philosophy outside Microsoft mirrors Buffett's: durable businesses with pricing power, bought at reasonable prices.

Bill Ackman

Ackman's core belief is that markets frequently misprice assets when the story around them is either too negative or too complicated. He looks for businesses he can understand deeply, with a gap between what the market thinks they're worth and what he thinks they're worth.

He's talked extensively about asymmetric bets — situations where you can be wrong and lose a small amount, but right and make a lot. He believes activist investing works because most company boards are too comfortable and most CEOs have too little accountability.

He thinks public pressure, when backed by real analysis, is a legitimate tool for creating value. Whether that makes him a hero or a villain depends on which company you ask.

Bill Gates

His core framework: read obsessively, think long-term, and separate emotion from analysis. He takes annual Think Weeks — solo retreats to a lake cottage in the Pacific Northwest where he reads papers and books for two weeks with no interruptions.

He publishes a reading list twice a year at gatesnotes.com. He has said that the best investment he ever made was paying $100,000 to take Warren Buffett to dinner every year.

Bill Ackman

Ackman runs highly concentrated books and uses leverage. That's the opposite of conservative.

He'll put 20–30% of the fund in a single position if he believes in it. He also uses options and credit derivatives — his March 2020 COVID hedge was built using credit default swaps, instruments most retail investors have never heard of.

He famously described his risk approach as: "I only invest when the downside is zero and the upside is unlimited" — which sounds great until you lose $4 billion on one trade. The honest version is: he's a high-conviction investor with a high tolerance for pain on the way to being right.

Bill Gates

Gates's risk tolerance is intellectual and deliberate rather than impulsive. He takes genuinely large bets — TerraPower on nuclear fission, billions into climate technology, the Gates Foundation's campaigns to eradicate diseases that kill millions — but only after intense research.

His Think Weeks exist to force slow, rigorous thinking on big decisions. At Microsoft, he kept enough cash on hand to run the company for a full year with zero revenue because he never wanted short-term survival pressure to force a bad long-term decision.

That discipline carries into his personal finances.

Bill Ackman

Ackman has a taste for the finer things and doesn't pretend otherwise. He owns a large Manhattan apartment, he's been photographed at high-end charity events, and his social circle overlaps with New York media, finance, and political elite.

He and his second wife, Neri Oxman, have a high public profile — she's a former MIT professor and design pioneer. He gave $25 million to Harvard (his alma mater), though the relationship became famously strained in 2023 when he led a very public campaign against Harvard's president over campus antisemitism, ultimately contributing to her resignation.

He is not a guy who stays quiet about anything.

Bill Gates

He wakes up early, exercises on a treadmill while watching documentaries, and reportedly does the dishes every night. He has said dishes are meditative.

For a man worth $130 billion, the emphasis on routine is either deeply grounded or very good PR. He drove himself to work at Microsoft for years and lived in a normal house long after he could afford otherwise.

Bill Ackman

The COVID hedge in March 2020 is the one. As markets started selling off in late February, Ackman quietly spent $27 million buying credit default swaps — basically insurance on corporate bonds defaulting if the economy collapsed.

He then went on CNBC on March 18, 2020, visibly emotional, and said "hell is coming." The market kept dropping. Three weeks later, he unwound the trade.

The $27 million had turned into $2.6 billion. That's roughly a 100x return in under a month.

He used the proceeds to buy stocks at the market bottom. He then made another fortune as markets recovered.

The whole sequence — hedge, cry on TV, buy the dip, profit — is one of the more remarkable individual trade sequences in recent hedge fund history.

Bill Gates

Microsoft Windows. The decision to license MS-DOS to IBM for the PC while retaining the right to sell it to other manufacturers was arguably the most lucrative business decision in tech history.

Every PC manufacturer then licensed Windows. Gates captured the entire PC market without building the hardware.

By 1999, Microsoft's market cap hit $616 billion.

Bill Ackman

The Valeant Pharmaceuticals disaster is the one. Ackman built a massive position in Valeant starting in 2015, eventually owning about $4 billion worth of shares.

His thesis was that Valeant's model — aggressively raising drug prices and cutting R&D — was brilliant. Congress, journalists, and eventually the SEC had a different view.

The stock collapsed from $260 to under $10. Ackman spent months publicly defending the position, appearing on CNBC repeatedly to explain why it would recover.

It didn't. He finally sold in 2017 at a loss of approximately $4 billion.

It's the most expensive public loss in hedge fund activism history. The lesson he's cited: don't get emotionally attached to a position, and be faster to recognize when the fundamental thesis has broken.

Bill Gates

Missing the internet. Microsoft was late and initially dismissive of the internet as a platform.

Gates eventually course-corrected and wrote the Internet Tidal Wave memo in 1995, redirecting the entire company toward internet strategy. But the delay allowed Netscape to establish footholds, and Microsoft's browser monopoly tactics led to the landmark antitrust case United States v.

Microsoft in 2000, which threatened to break up the company.

Bill Ackman

Bill Ackman grew up in Chappaqua, New York, the son of a real estate finance chairman. He was a history major at Harvard — class of 1988 — then went straight to Harvard Business School.

His first venture was Gotham Partners, a real estate and value investing fund he started in 1992 with a Harvard classmate. It was a disaster.

The fund made concentrated bets on illiquid real estate and had to be wound down by 2003 under serious investor pressure and SEC scrutiny.

He didn't quit. In 2004 he launched Pershing Square Capital Management, this time with a clearer focus: take large stakes in companies, go public with his thesis, and use activist pressure to force management changes.

The approach worked. His reputation was built on detailed, public investment presentations — sometimes running 100+ slides — that became must-reads on Wall Street.

He turned activist investing into something that felt more like journalism than finance: research a company, find what's broken, publish everything, and bet heavily on being right.

Bill Gates

Bill Gates was born in Seattle in 1955. He taught himself to program on a PDP-10 at age 13.

He enrolled at Harvard in 1973, dropped out in 1975, and moved to Albuquerque with Paul Allen to found Microsoft. Their break came when they licensed an operating system to IBM for the original PC — and crucially, retained the rights to sell it to anyone else.

That decision made Microsoft. Windows became the standard operating system for the world.

Gates became the world's richest person in 1995 and held that title for much of the next 15 years. He transitioned out of Microsoft's day-to-day around 2000 and fully moved into philanthropy via the Gates Foundation.

Bill Ackman

Pershing Square Capital Management is his flagship hedge fund, managing around $16 billion. His most famous public positions have included Canadian Pacific Railway, where he pushed successfully for a new CEO and a turnaround that made Pershing Square hundreds of millions.

He held a massive position in Valeant Pharmaceuticals from 2015 to 2017 — which will come up again. He took a huge bet on General Growth Properties during the 2008 financial crisis when no one else would touch it.

That one returned over $1 billion.

He has also done business on the other side: Pershing Square Holdings is his publicly listed vehicle on Euronext Amsterdam, which lets retail investors access his fund — unusual for a hedge fund of this size. He's been a major Burger King and Restaurant Brands International investor, and he backed Fannie Mae and Freddie Mac preferred shares in a long-running legal battle with the government.

Bill Gates

Microsoft (co-founder, former CEO and chairman). Cascade Investment LLC (his personal investment vehicle).

Bill & Melinda Gates Foundation (co-chair). Major holdings through Cascade include Canadian National Railway, Deere & Company, and significant farmland.

Early Microsoft equity remains a massive portion of his net worth.

Bill Ackman

Harvard College, BA in History, 1988. Harvard Business School, MBA, 1992.

He's been a major Harvard donor — and major Harvard critic — throughout his career. The irony of his most public fight being with his own alma mater was not lost on anyone.

Bill Gates

Harvard University — studied mathematics and computer science. Dropped out in 1975 after his sophomore year to found Microsoft.