Carl Icahn

Icahn buys undervalued companies with bad management. His thesis is consistently the same: there is enormous value being destroyed by entrenched executives who are more interested in keeping their jobs than returning value to shareholders.

He buys enough stock to force a confrontation. Sometimes management cleans itself up just from the threat of his involvement.

Sometimes he installs new people. Sometimes he forces a full sale of the company.

His version of value investing is more aggressive than Graham''s or Buffett''s. He doesn''t wait for the market to recognise value.

He forces the recognition. He is comfortable with conflict in a way most investors are not.

He sees confrontation with management as part of the job — not an unfortunate side effect of it.

Mark Zuckerberg

Zuckerberg does not invest in the traditional sense — he builds and holds. He controls Meta through a dual-class share structure that gives him roughly 54% of voting power with less than 15% economic ownership, meaning no board or shareholder can remove him regardless of how the stock performs.

He has made massive bets inside Meta — on mobile (right), Instagram (very right), WhatsApp (right), VR/metaverse (wrong so far), and AI (still playing out). His investment thesis is that social connectivity is a fundamental human need and whoever owns the infrastructure owns everything.

Carl Icahn

He genuinely believes management teams destroy shareholder value through complacency, self-dealing, and entrenchment. He sees himself as a corrective force — not a vulture, but a mechanism by which markets hold management accountable.

Whether that''s how it looks from inside the companies he targets is a different question. His rules: buy when nobody else wants it, apply pressure to unlock the value, sell when the value is recognised.

Don''t get sentimental about positions. Don''t let management tell you the company is more complex than it looks.

Mark Zuckerberg

Zuckerberg thinks in decades, not quarters. His core belief is that the most important technology of the next century is whoever connects people at scale — first through social networks, then through AR/VR, and now through AI agents.

He is willing to absorb years of losses on bets he believes in. He says he would rather make a big bet and be wrong than be timid and miss the next platform shift.

Carl Icahn

He concentrates. He uses leverage.

He''s comfortable with positions that make other investors deeply uncomfortable. He''s also comfortable being wrong in public — he''s had positions go spectacularly badly and he doesn''t hide from them.

His Hertz position went bankrupt during COVID. His Herbalife long was a very public, very watched position on the opposite side of Bill Ackman''s short.

He doesn''t bluff. When he says he''s going to fight, he fights.

Mark Zuckerberg

Zuckerberg spent $36 billion on Reality Labs — VR and AR — between 2019 and 2023, with little to show in revenue. He did not flinch.

He also bet Facebook's entire business model on going mobile in 2012, acquired Instagram for $1 billion when it had 13 employees and no revenue, and has held through Congressional hearings, advertiser boycotts, and multiple existential challenges from competitors. His personal financial risk is minimized by his dual-class share structure — he controls voting power regardless of what the stock does, so no board or activist investor can force his hand.

He can lose at scale for as long as he believes the thesis.

Carl Icahn

He lives in Sunny Isles Beach, Florida. He works ferociously hard and has done so into his late 80s.

He''s a hands-on manager — not someone who delegates. He famously said: "If you want a friend on Wall Street, get a dog." He has a Maltese named Tiger.

He''s been a prolific poker player and was once considered one of the best amateur players in New York. He remarried in 2012; his current wife is Gail Golden.

He''s given some money to charity but not at the scale of Buffett or Gates — he''s made no secret of prioritising returns over philanthropy.

Mark Zuckerberg

He wore the same grey t-shirt every day for years — he said it reduced decision fatigue. He trains MMA and Brazilian jiu-jitsu seriously, competing in actual tournaments.

He wakes up early, spends mornings with his family, and starts work at 8am. He has spoken about designing his schedule to protect creative work in the mornings.

He reportedly does not check email first thing.

Carl Icahn

Apple. In 2013 he disclosed a $1.5 billion stake in Apple and published an open letter to Tim Cook urging a larger share buyback.

Apple eventually announced a significantly expanded buyback program. The stock rose.

Icahn made approximately $2 billion on the position. He didn''t have to engineer a hostile takeover — just making his involvement public was enough to move one of the largest companies in the world.

Mark Zuckerberg

Acquiring Instagram for $1 billion in 2012. Instagram was growing fast, potentially threatening Facebook's dominance with younger users.

Facebook bought it. It now generates an estimated $40-60 billion in annual revenue.

Many consider it the best acquisition in tech history on a return basis — $1 billion in for what became a $100B+ asset.

Carl Icahn

TWA. He took over Trans World Airlines in 1985 using a leveraged buyout, extracted cash from the company to pay back the acquisition debt, and sold the valuable London routes to American Airlines for $445 million.

By the time he was done, TWA was a financially gutted airline. It went bankrupt in 1992, again in 1995, and was absorbed by American Airlines in 2001.

Icahn personally made hundreds of millions. The airline''s employees and creditors did not.

He''s defended his actions as legal. Legal and good for everyone are not always the same thing.

Mark Zuckerberg

The metaverse bet. From 2021 to 2023, Meta spent over $50 billion on Reality Labs — its VR and metaverse division — and generated minimal revenue.

The division lost $16 billion in 2023 alone. Meta's stock fell nearly 75% at its 2022 trough.

Zuckerberg was widely mocked, called the metaverse a disaster, and faced enormous internal and external pressure. He then pivoted hard to AI and the stock recovered.

The metaverse losses remain one of the most expensive executive vanity projects in corporate history.

Carl Icahn

Carl Icahn grew up in Far Rockaway, Queens. His father was a failed opera singer who became a synagogue cantor.

Icahn studied philosophy at Princeton — graduated 1957 — then enrolled in NYU School of Medicine before dropping out after two years to join the army. He became a stockbroker at Dreyfus & Co.

in 1961, saved $400,000, and bought a seat on the New York Stock Exchange in 1968.

He spent the early years running option arbitrage — finding and exploiting small mispricings. He was very good at it.

In the late 1970s he pivoted to a bigger game: buying large stakes in undervalued companies and forcing management changes. His first major target was Tappan Company in 1979.

By the mid-1980s he was feared by corporate boards across America. Oliver Stone''s Gordon Gekko in Wall Street is directly based on the era Icahn created.

Mark Zuckerberg

Mark Zuckerberg launched Facebook from his Harvard dorm in February 2004. By the end of 2004, the site had 1 million users.

He turned down a $1 billion acquisition offer from Yahoo in 2006. By 2012, Facebook went public at a $104 billion valuation — the largest tech IPO in history at the time.

The stock immediately fell 50%. It then recovered to become one of the most valuable companies in the world.

In 2012, Facebook acquired Instagram for $1 billion (now worth over $100 billion). In 2014, it acquired WhatsApp for $19 billion.

In 2021, he rebranded the parent company to Meta to signal a pivot to the metaverse — a move that cost over $50 billion in investment and destroyed significant shareholder value before the company course-corrected toward AI.

Carl Icahn

Icahn Enterprises is his publicly traded holding company. He''s been chairman since 1987.

Some of his most famous investments: TWA, which he took over in 1985, stripped its most valuable routes to pay back the debt used to acquire it, and left financially hollowed out — it went bankrupt twice after his tenure. Texaco, where he forced a settlement that paid shareholders.

Apple, where he took a $1.5 billion position in 2013 and published an open letter to Tim Cook demanding a larger share buyback. Apple eventually expanded the buyback.

The stock rose. Icahn made roughly $2 billion on the position without engineering a hostile takeover — the threat of his involvement was enough to move a $500 billion company.

He''s also had notable losses. Hertz went bankrupt during COVID while he held a large position.

He lost hundreds of millions.

Mark Zuckerberg

Meta Platforms (CEO and controlling shareholder — holds majority voting control through supervoting shares). Key acquisitions: Instagram (2012, $1B), WhatsApp (2014, $19B), Oculus VR (2014, $2B).

Chan Zuckerberg Initiative (co-founded with wife Priscilla Chan — philanthropic LLC).

Carl Icahn

Princeton University, BA in Philosophy, 1957. NYU School of Medicine, dropped out after two years.

He''s credited Princeton''s philosophy training with teaching him to question conventional wisdom — which shows up directly in how he argues with corporate boards.

Mark Zuckerberg

Harvard University — studied computer science and psychology. Dropped out in 2004 to move Facebook to Palo Alto.