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.

David Einhorn

Einhorn is a long/short fundamental investor. On the long side, he looks for cheap, misunderstood businesses where the market has gotten the story wrong.

On the short side, he looks for companies with accounting irregularities, unsustainable business models, or management teams making misleading claims. His edge historically was doing the detailed work that others skipped: actually reading the footnotes, actually questioning the numbers, actually calling the bluff in public.

He goes public with his short theses, which most short-sellers avoid. He presents at conferences.

He names names. This is controversial — critics say it''s market manipulation, supporters say it''s journalism.

The Allied Capital and Lehman Brothers situations suggest it''s at least occasionally correct.

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.

David Einhorn

Einhorn believes the market frequently misprices securities because most investors are lazy or short-term focused. His philosophy is that detailed, patient fundamental research creates an edge — not access, not algorithms, not macro calls.

He also believes that companies with accounting problems eventually get found out. He has framed his public short campaigns as a form of market policing: if management is lying, someone needs to say so.

He''s been called a hero and a villain for the same trade.

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.

David Einhorn

Einhorn runs a concentrated long/short book with meaningful leverage. He''s comfortable holding short positions for years and absorbing paper losses while waiting for a thesis to play out.

He has described his approach as being comfortable with uncertainty as long as the fundamental analysis is sound. The problem is that being fundamentally right and being market-right are two different things, and the gap between them can be expensive.

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.

David Einhorn

Einhorn is known for being relatively frugal for a hedge fund manager of his stature. He''s a serious poker player, not a yacht person.

He has donated millions to various causes, including a significant amount through his winning poker tournament proceeds. He lives in New York.

He''s notably down-to-earth compared to the hedge fund world''s flashier personalities — no famous cars, no tabloid drama.

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.

David Einhorn

The Lehman Brothers short is the definitive win. Einhorn began shorting Lehman''s stock in early 2008.

He presented his thesis publicly at a Ira Sohn Conference in May 2008, citing specific accounting concerns about how the firm was valuing its real estate exposure. Lehman''s stock fell immediately.

The firm''s CEO famously called Einhorn a "short and distort" operator. On September 15, 2008, Lehman Brothers filed for bankruptcy.

Greenlight made over $1 billion on the trade. It is one of the most vindicated public short positions in financial history.

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.

David Einhorn

The post-2015 period is where the story gets complicated. Greenlight significantly underperformed from 2015 onward.

The fund lost money in 2015, 2018, and 2020. Part of this was a structural problem: value investing broadly underperformed during the growth stock boom.

Part of it was specific bets that went wrong. His short of Tesla was particularly costly — Tesla''s stock rose dramatically while Einhorn remained convinced the company was overvalued, costing the fund hundreds of millions.

He compared Tesla to the fraud companies he''d exposed previously. Tesla kept going up anyway.

The difference between "fundamentally wrong" and "stock going up" is an expensive distinction to make.

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.

David Einhorn

David Einhorn grew up in Demarest, New Jersey, in a family of academics and professionals. He attended Cornell University, graduating summa cum laude with a degree in government.

After a brief stint at Donaldson, Lufkin & Jenrette, an investment bank, he started Greenlight Capital in 1996 at age 27 with $900,000 raised from family and friends.

The fund performed well from the start. Einhorn built a reputation for meticulous fundamental research — reading SEC filings obsessively, questioning management in earnings calls, and occasionally going public with short theses that embarrassed companies.

His 2002 short of Allied Capital, a business development company he argued was mismarking its loan book, started a years-long battle with the company and eventually the SEC. He wrote a book about it.

He was ultimately right.

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.

David Einhorn

Greenlight Capital is his hedge fund, managing approximately $1.5 billion today — down significantly from its peak of over $12 billion before a decade of underperformance. Greenlight runs a long/short equity strategy, meaning it simultaneously bets on stocks going up and stocks going down.

The short side is where Einhorn has built his public reputation.

He is also deeply involved in poker. He has finished in the money at the World Series of Poker multiple times, made the final table of the Main Event in 2012, and has won over $4 million in tournament poker.

He donated his 2006 World Series earnings to charity. He has said publicly that poker and investing require the same skills: reading information, managing uncertainty, and knowing when to fold.

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.

David Einhorn

Cornell University, BA in Government, summa cum laude, 1991. He was a member of the Telluride Association, an honors society that placed particularly sharp students in a semi-independent living and learning program.

He has described his Cornell education as teaching him how to think, not what to think — which is, coincidentally, what good investing requires.