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Bill Ackman

Bill Ackman (link) by Business Insider is licensed CC BY-SA 4.0 (link)
Nationality:

American
Born:

1966
Occupation:

Investor, Hedge Fund Manager, Founder of Pershing Square Capital Management

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William “Bill” Ackman is a political donor, pro-Israel activist, investor, and hedge fund manager at Pershing Square Capital Management. Ackman in known for shorting stocks, betting they would fall in value while pushing negative media stories about those companies. Ackman is also an “activist” investor who has pushed for policy and leadership changes at companies in which he owns stock. 1

While Ackman has traditionally supported Democrats in the past, he has been a supporter of Israel and President Donald Trump’s second term. 1

Background

Bill Ackman is CEO and portfolio manager at Pershing Square Capital Management (“Pershing Square”), a hedge fund firm he founded in 2003. 2 Previously, Ackman co-founded and managed the hedge fund firm Gotham Partners Management. 2 He began his career in real estate investment banking at Ackman Brothers and Singer Inc. 2 Ackman has a B.A. from Harvard College and an MBA from Harvard Business School. 2 In 2025, Forbes estimated Ackman to be worth $9.3 billion. 1

Pershing Square

In 2005, Ackman and Pershing Square purchased a large share of Wendy’s stock and pressured management at the company to spin off its Tim Horton’s brand. 3 After Wendy’s agreed, Ackman sold his shares, making a large profit. The Wendy’s stock price later fell, 3 leading critics to claim that Ackman was responsible for leaving Wendy’s without the growing Tim Horton’s brand. 3

In 2008, Ackman and Pershing Square purchased a large share of Target Corporation and pressured the company to sell its credit card portfolio. 3

At the end of 2021, Pershing Square’s holdings were valued at $57 billion. 4 Pershing Square has made controversial investments and trades such as a short-sale of Herbalife in 2012. 4 (Short selling is a process by which one borrows shares for a set time to sell them, with the goal of repurchasing the shares to cover the loan at a lower price; short-sellers profit if the stock price of the company falls.) 5 Ackman and Pershing Square shorted about $1 billion of Herbalife stock, claiming the company operated as a pyramid scheme. 6 Ackman hired lobbyists attempting to convince Congress to investigate Herbalife, which resulted in Senator Ed Markey (D-MA) asking the Federal Trade Commission to investigate the company. 7 After five years and little change in stock price, Ackman’s Pershing Square dropped their short position in Herbalife. 8

In January 2022, Ackman and Pershing Square acquired 3.1 million shares of Netflix valued at $1.1 billion. 9 In April 2022, Ackman and the firm sold all the shares resulting in a $400 million loss in three months. 10

In 2022, Ackman announced that he planned to abandon high-profile investor activism. 11

As of September 2025, Ackman and Pershing Square oversaw some $30 billion in assets for pension funds, endowments and wealthy investors, invested in about a dozen companies. 11

In September 2025, VistaShares announced that it created an exchange-traded fund (ETF) that mirrored the publicly disclosed holdings of Ackman and Pershing Square. 11

Views

In 2016, Bill Ackman wrote an op-ed supporting former New York City Mayor Michael Bloomberg (who did not run that year) over former Secretary of State Hillary Clinton for the Democratic nomination for President 12

In 2017, Ackman got into a heated exchange with then-former Vice President Joe Biden. 13 After a comment by Ackman that Biden took to be about his late son, Biden called Ackman an expletive and told him to “just shut the hell up.” 14 Ackman did not donate to Biden’s 2020 presidential election campaign. 15

In March 2020, Ackman called for President Donald Trump to shut down the country due to the coronavirus, stating that without lockdowns, “America will end as we know it.” 16 It is estimated that Pershing Capital made $3.8 billion on trades involving COVID-related market movements. 17

In 2021, Ackman angered some through a series of tweets supporting Kyle Rittenhouse during Rittenhouse’s homicide trial in Wisconsin. 18 Rittenhouse was later found not guilty on all counts. 19

In April 2025, Ackman warned of an “economic nuclear winter” over tariffs imposed by President Donald Trump. Ackman urged President Trump to pause the tariffs for 90 days. Ackman warned that Trump’s tariffs had threatened to undermine investor confidence in the U.S. He urged President Trump to negotiate with other countries and attract trillions in investment to the U.S. 20

In July 2025, Ackman donated $10 million to the International Tennis Hall of Fame after he participated in a widely mocked doubles match. Ackman claimed that his poor play had drawn lots of attention to the Hall of Fame. 21

In August 2025, Ackman proposed combining government-backed mortgage companies Fannie Mae and Freddie Mac, claiming that it would reduce mortgage rates and achieve huge synergies in their operations and the mortgage price. Ackman, who has held stakes in both companies for over a decade, also said that a merger would reduce regulatory costs since there would only be one company for the federal government to regulate. 22

In September 2025, Ackman said he was “very bullish” on Israel after a visit. He owns a five percent stake in the Tel Aviv Stock Exchange and he has an Israel-born wife. 23

Pro-Israel Advocacy

Following attacks against Israel by the terror group Hamas on October 7, 2023, Ackman released a statement on X, formerly Twitter, calling for Harvard University to release the names of students who signed a letter blaming Israel for the attacks. 24 Ackman also criticized former Harvard president Claudia Gay for her congressional testimony in December 2023, which she gave along with Massachusetts Institute of Technology (MIT) president Sally Kornbluth and former University of Pennsylvania (UPENN) President Liz Magill, over the response to a rise in antisemitic incidents on college campuses following the October 7 attacks. 24 25 Ackman later called for Gay’s resignation after several sources, including The Washington Free Beacon and Harvard’s student paper, alleged evidence of plagiarism on several of Gay’s academic papers dating back to the 2000’s. Gay would step down from her position on January 2, 2024. 24 26

Ackman would go on to criticize diversity, equity, and inclusion (DEI) programs which Harvard and other universities promoted. The criticism drew weekly protests against Ackman by Al Sharpton. 27

In January 2024, a report by Business Insider claimed that Ackman’s wife, professor Neri Oxman, plagiarized her 2010 MIT dissertation by stealing, “sentences and whole paragraphs from Wikipedia” 24 as well as improperly quoting from other academic papers. 24 Oxman responded to the report on X, stating, “I regret and apologize for these errors,” 24 and argued she did not “place the subject language in quotation marks, which would be the proper approach for crediting the work.” 24 Ackman also responded on X by claiming the allegations by Business Insider against Oxman don’t “strike me as plagiarism,” 24 and further commented, “I am sure that when Neri wrote her dissertation she thought that there was nothing wrong with using Wikipedia as a dictionary.” 24 He later claimed that academic papers by Ivy League staff should be checked by Artificial Intelligence (AI) software to check for plagiarism. 24

In May 2025, Ackman supported the decision by the second Trump administration to withhold federal funds from Harvard University. Ackman also criticized Harvard’s investments claiming the school’s endowment was “poorly invested.” 28

Election Campaign Spending

2024 Election Cycle

In January 2024, Ackman donated $1 million to a super PAC supporting then-U.S. Rep. Dean Phillips’s (D-MN) primary challenge to then-President Joe Biden. He also called on President Biden to step aside and not seek reelection. 30

2025 New York City Mayor’s Race

In April 2025, Ackman donated $250,000 to the Fix the City PAC which supported former New York Governor Andrew Cuomo for New York City mayor. 31

In June 2025, Ackman promised to fund a centrist candidate for New York City mayor after socialist Zohran Mamdani won the Democratic Party nomination for mayor. Ackman asked his social media followers to crowdsource some names for potential Mamdani opponents, and he said he would do a poll of followers based on the suggestions. Ackman said he wanted to do the crowdsourcing because he didn’t want his support for President Donald Trump to taint any potential candidate he would support. 32

In July 2025, Ackman called on Andrew Cuomo to leave the race, claiming that New York City Mayor Eric Adams (D) could defeat Mamdani. Ackman criticized Curomo’s “body language, his subdued energy and his proposals to beat Mamdani, [make it clear] that he is not up for the fight.” 33

In September 2025, Ackman called on Mayor Adams to end his reelection campaign and he announced his endorsement of former Governor Cuomo for mayor. Ackman said that Mayor Adams’s poll numbers had deteriorated since the Democratic primary and that Adams could not beat Democratic nominee and self-described socialist Zohran Mamdani. 34

Earlier Political Contributions

Ackman has donated more than $600,000 to Democratic campaigns including those of Barack Obama, Al Gore, former South Bend mayor Pete Buttigieg, former Rep. Beto O’Rourke (D-TX), former Chicago mayor Rahm Emanuel, Sen. Chuck Schumer (D-NY), and the Democratic Senatorial Campaign Committee. 15

References

  1.  “William Ackman.” Forbes. Accessed September 29, 2025. https://www.forbes.com/profile/william-ackman/.
  2. “William A. Ackman.” Pershing Square Foundation. Accessed June 8, 2022. https://pershingsquarefoundation.org/people/william-a-ackman-2/.
  3. Serres, Chris. “William Ackman: Targeting Target.” Star Tribune. January 13, 2008. Archived from the original May 29, 2012. Accessed June 28, 2022. https://web.archive.org/web/20120529164307/http://www.startribune.com/printarticle/?id=13715691
  4. Schultz, Hank. “Herbalife Foe Ackman Swears Off Short Selling Strategy.” Nutra Ingredients. April 5, 2022. Accessed June 9, 2022. https://www.nutraingredients-usa.com/Article/2022/04/05/herbalife-foe-ackman-swears-off-short-selling-strategy#.
  5. “Short Sale.” Cambridge English Dictionary. Accessed June 30, 2022. https://dictionary.cambridge.org/us/dictionary/english/short-sale.
  6. Moyer, Liz. “Five Years After Brawl with Carl Icahn, Bill Ackman Exits Losing Bet Against Herbalife.” CNBC. February 28, 2018. Accessed June 9, 2022. https://www.wcnc.com/article/news/nation-now/five-years-after-brawl-with-carl-icahn-bill-ackman-exits-losing-bet-against-herbalife/465-a8f6e5b6-2824-40b5-9239-d339ecaeb235; Schultz, Hank. “Herbalife Foe Ackman Swears Off Short Selling Strategy.” Nutra Ingredients. April 5, 2022. Accessed June 9, 2022. https://www.nutraingredients-usa.com/Article/2022/04/05/herbalife-foe-ackman-swears-off-short-selling-strategy#.
  7. “Ackman Outspent by Herbalife in Lobbying Battle.” CNBC. March 10, 2014. Accessed June 9, 2022. https://www.cnbc.com/2014/03/10/ackman-outspent-by-herbalife-in-lobbying-battle.html.
  8. [1] Schultz, Hank. “Herbalife Foe Ackman Swears Off Short Selling Strategy.” Nutra Ingredients. April 5, 2022. Accessed June 9, 2022. https://www.nutraingredients-usa.com/Article/2022/04/05/herbalife-foe-ackman-swears-off-short-selling-strategy#.
  9. Bill Ackman Tweet. www.twitter.com. January 26, 2022. Accessed June 8, 2022. https://twitter.com/BillAckman/status/1486460691519361024?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1486460691519361024%7Ctwgr%5E%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.wsj.com%2Farticles%2Fwilliam-ackman-takes-stake-in-netflix-11643236690; Spangler, Todd. “Hedge Fund Manager Bill Ackman Sells Entire Netflix Stake, Taking $400 Million Loss.” Variety. April 21, 2022. Accessed June 8, 2022. https://variety.com/2022/digital/news/bill-ackman-sells-netflix-stake-loss-1235237715/.
  10. Spangler, Todd. “Hedge Fund Manager Bill Ackman Sells Entire Netflix Stake, Taking $400 Million Loss.” Variety. April 21, 2022. Accessed June 8, 2022. https://variety.com/2022/digital/news/bill-ackman-sells-netflix-stake-loss-1235237715/.
  11. Herbst-Bayliss, Svea, and Suzanne McGee. “Vistashares Launches ETF Tracking Stock Bets of Hedge Fund Activist Bill Ackman .” Reuters, September 9, 2025. https://www.reuters.com/sustainability/boards-policy-regulation/vistashares-launches-etf-tracking-stock-bets-hedge-fund-activist-bill-ackman-2025-09-09/.
  12. La Roche, Julia. “Billionaire Bill Ackman Wrote an Op-Ed in Support of Bloomberg for President Because ‘America is Burning.’” Business Insider. February 11, 2016. Accessed June 8, 2022. https://www.businessinsider.com/ackman-op-ed-bloomberg-for-president-2016-2.
  13. Cullen, Terrence. “Joe Biden Gets into Tense Exchange With billionaire Bill Ackman.” New York Daily News. June 24, 2017. Accessed June 9, 2022. https://www.nydailynews.com/news/politics/joe-biden-tense-exchange-billionaire-bill-ackman-article-1.3274531.
  14. Schwartz, Brian. “Joe Biden’s Beef with Joe Ackman Sparks Heated Exchange and Presidential Chatter.” Fox Business. June 27, 2017. Accessed June 9, 2022. https://www.foxbusiness.com/politics/joe-bidens-beef-with-bill-ackman-sparks-heated-exchange-and-presidential-chatter.
  15. “Bill Ackman.” Center for Responsive Politics. Accessed June 13, 2022. https://www.opensecrets.org/donor-lookup/results?name=William+ackman.
  16. “’Hell is Coming – Bill Ackman Has Dire Warning for Trump, CEOs if Drastic Measures Aren’t Taken Now.” CNBC. March 18, 2020. Accessed June 8, 2022. https://www.cnbc.com/2020/03/18/bill-ackman-pleads-to-trump-to-increase-closures-to-save-the-economy-shut-it-down-now.html.
  17. Weil, Dan. “Hedge Funder Ackman Makes $3.8 Billion on Covid Trades.” The Street. February 1, 2022. Accessed June 8, 2022. https://www.thestreet.com/investing/ackman-3-billion-dollars-covid-trades; Hartmans, Avery. “Billionaire Bill Ackman Calls for Trump to Concede: ‘Think About Your Legacy and What is Best for the Country.” Business Insider. November 9, 2020. Accessed June 8, 2022. https://www.businessinsider.com/bill-ackman-urges-trump-to-concede-election-2020-11.
  18. Pesce, Nicole Lyn. “Bill Ackman: Kyle Rittenhouse is ‘Telling the Truth’ and ‘Acted in Self-Defense’ in Viral Twitter Feed.” Market Watch. November 12, 2021. Accessed June 9, 2022. https://www.marketwatch.com/story/bill-ackman-kyle-rittenhouse-is-telling-the-truth-and-acted-in-self-defense-in-viral-twitter-thread-11636737750.
  19. Hymes, Clare. “Kyle Rittenhouse Found Not Guilty of All Charges in Kenosha Shootings.” CBS News. CBS Interactive, November 20, 2021. https://www.cbsnews.com/live-updates/kyle-rittenhouse-verdict-acquitted-all-charges/.
  20. FitzGerald, James FitzGerald & Lisa, and Lisa Lambert. “Billionaire Trump Backer Bill Ackman Warns of ‘economic Nuclear Winter’ over Tariffs.” BBC News, April 7, 2025. https://www.bbc.com/news/articles/c2lzjnj79rdo.
  21.  Hult, Ava. “Bill Ackman to Give $10m to Tennis Hof after Tournament Fiasco.” Front Office Sports, July 13, 2025. https://frontofficesports.com/bill-ackman-gives-10m-to-tennis-hall-of-fame-after-tournament-fiasco/.
  22. “Investor Bill Ackman Proposes Combining Fannie Mae and Freddie Mac .” Reuters, August 10, 2025. https://www.reuters.com/business/finance/investor-bill-ackman-proposes-combining-fannie-mae-freddie-mac-2025-08-10/.
  23. “Your Daily Phil: Capping Recent Visit, Bill Ackman Says He’s ‘bullish’ on Israel.” eJewishPhilanthropy, September 15, 2025. https://ejewishphilanthropy.com/your-daily-phil-capping-recent-visit-bill-ackman-says-hes-bullish-on-israel/.
  24. Deese, Kaelan. “Who is Bill Ackman? The hedge fund billionaire who has MIT and Business Insider in his sights.” The Washington Examiner, January 7, 2024. https://www.washingtonexaminer.com/news/2789165/who-is-bill-ackman-the-hedge-fund-billionaire-who-has-mit-and-business-insider-in-his-sights/
  25. Delouya, Samantha. “After Harvard and Penn president resignations, focus of ire shifts to MIT’s Kornbluth.” CNN Business, January 3, 2024. https://edition.cnn.com/2024/01/03/business/sally-kornbluth-pressure-claudine-gay-resignation/index.html
  26. Egan, Matt. “Harvard President Claudine Gay resigns after plagiarism and campus antisemitism accusations.” CNN Business, January 3, 2024. https://www.cnn.com/2024/01/02/business/claudine-gay-harvard-president-resigns/index.html
  27. Kornick, Lindsay. “Al Sharpton Protests Bill Ackman: ‘declared War against All of Us’ by Going after Dei.” Fox News, January 4, 2024. https://www.foxnews.com/media/al-sharpton-bill-ackman-declared-war-dei?msockid=02650e216a0a61c23f001a866b026056.
  28. “Bill Ackman Says Trump Is Doing ‘precisely the Right Thing’ as Admin Freezes Billions of Dollars for Harvard.” New York Post, May 6, 2025. https://nypost.com/2025/05/06/business/bill-ackman-says-harvard-not-entitled-to-federal-funds/.

  30. In July 2024, Ackman endorsed Donald Trump for president. The decision to endorse Trump came after Ackman met with Trump, and Ackman criticized then-President Joe Biden. Ackman made the announcement after the failed assassination attempt against Trump in Butler, Pennsylvania. 29  Arias, Pilar. “Billionaire Bill Ackman Publicly Endorses Trump Following Assassination Attempt.” Fox Business, July 14, 2024. https://www.foxbusiness.com/business-leaders/billionaire-bill-ackman-publicly-endorses-trump-following-assassination-attempt

  31. Coltin, Jeff. “Trump Backer Bill Ackman Supports Cuomo’s Mayoral Bid with $250K Donation.” Politico, April 14, 2025. https://www.politico.com/news/2025/04/14/bill-ackman-andrew-cuomo-donation-00290306.
  32. Revell, Eric. “Bill Ackman Promises to Fund Centrist Candidate to Defeat Socialist Mamdani in NYC Mayoral Race.” Fox Business, June 26, 2025. https://www.foxbusiness.com/politics/bill-ackman-promises-fund-centrist-candidate-defeat-socialist-mamdani-nyc-mayoral-race.
  33. Crisp, Elizabeth. “Bill Ackman Urges Andrew Cuomo to Step aside from NYC Mayoral Race.” The Hill, July 3, 2025. https://thehill.com/homenews/campaign/5383572-bill-ackman-andrew-cuomo-nyc-mayoral-race/.
  34. Reilly, Patrick, and Craig McCarthy. “Bill Ackman Backs Cuomo for NYC Mayor and Urges Adams to Step aside in Stunning U-Turn.” New York Post, September 6, 2025. https://nypost.com/2025/09/05/us-news/bill-ackman-backs-cuomo-for-nyc-mayor-urges-adams-to-step-aside/.
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