The story
Founded by Kenneth C. Griffin in 1990, in Chicago.1
Founding, 1990–2000
Griffin started his trading career out of his dorm room at Harvard University in 1987, trading convertible bonds. As a sophomore, he hooked a satellite dish to the roof of his dormitory. After graduating with a degree in economics, Griffin joined Chicago-based hedge fund Glenwood Partners. Citadel was started with $4.6 million in capital. Citadel was originally named Wellington Financial Group after its flagship fund. The company name was changed to Citadel in 1994. Within eight years, the firm had more than $2 billion in assets under management.
In 1998, Citadel started requiring investors to accept terms that "significantly restrict[ed] their ability to withdraw their capital", according to Institutional Investor. When hedge fund Long Term Capital Management collapsed later that year, Citadel's capital lockdown made it "a rare buyer, as desperate hedge funds unloaded bond inventory".
2001–2010
In 2001, Griffin began recruiting the energy traders from Enron the day after it collapsed for a new business including "a team of traders, meteorologists and researchers" building amongst the industry's biggest energy trading groups at the time.
In 2006, Citadel and JPMorgan Chase took over the energy portfolio and division of failed hedge fund Amaranth Advisors, which had suffered a 65% ($6 billion) loss in assets. In November 2006, Citadel issued $2 billion of investment-grade bonds to borrow money at a lower rate than otherwise able.
In 2007, Citadel invested $2.5 billion in E-Trade. This transaction included acquiring E-Trade's securitized subprime mortgages, collateralized debt obligations (CDOs), and second lien loans, as well as 12.5% senior unsecured notes, and 84,687,686 shares of common stock (equal to 19.99% of the then currently outstanding shares). Citadel received a seat on the board of directors. Citadel sold its remaining stake in E*Trade in 2013.
During the 2008 financial crisis, for 10 months, Griffin barred his investors from withdrawing money, attracting criticism. At the peak of the crisis, the firm was losing "hundreds of millions of dollars each week". It was leveraged 7:1 and the biggest funds at Citadel finished 2008 down 55%. However, they rebounded with a 62% return in 2009.
2011–2020
On January 17, 2012, Citadel's flagship funds, Citadel Kensington Global Strategies Fund Ltd and Citadel Wellington LLC, crossed their respective high watermarks, earning back the 50% of assets lost during the 2008 financial crisis. Having made up the losses, Citadel could once again charge client fees for managing their money and take a percentage of profits. Citadel under Griffin's leadership was reported as differentiating from hedge funds rivals post 2008 financial crisis with an "aggressive expansion". Starting at the beginning of 2014, over an 18 months period the hedge fund's assets under management increased $10 billion; from $16 billion to $26 billion as a result of "a 29% rise for its main hedge funds and a flow of new cash". In January 2020, Citadel Securities paid a $97 million settlement to China, after Chinese regulators ended a long-standing investigation into Citadel and other companies.
In 2014, Citadel became the first foreign hedge fund to complete a yuan fundraising as part of a program to allow Chinese investors to invest in overseas hedge funds.
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In July 2020, during the coronavirus pandemic, Citadel created a "bubble" for a class of 100 interns by renting out a luxury resort in Wisconsin.
Former companies
Citadel Solutions was Citadel's fund administration arm. The company changed its name to Omnium in 2009 and was sold to Northern Trust in 2011.
Citadel Technology, established in 2009, was a wholly owned and independently operated affiliate of Citadel. It offered investment management technology, developed internally at Citadel, to a wide range of firms and funds. In 2013, Citadel Technology announced a partnership with REDI. The partnership combines Citadel's order management system (OMS) with REDI's execution management capabilities (EMS).
Aptigon Capital was formed in 2016 after Citadel LLC hired 17 portfolio managers from its rival Visium Asset Management which was in the process of closing down. It was originally led by Richard Schimel until he left Citadel in 2018; being replaced by Eric Felder. Felder led the unit until its closure in 2019 after Felder's departure from the company.
2021–present
In January 2021, Citadel and Point72 Asset Management invested $2.75 billion in Melvin Capital, after Melvin Capital lost 53% of its value owing to the GameStop short squeeze.
In 2021, Citadel ranked second among the top money managers for net gains.
In a letter to employees on June 23, 2022, Griffin announced they would be moving their headquarters to Miami, Florida, due to a more favorable business climate and increased crime complaints in Chicago.
In December 2022, Citadel signed a deal with Vornado Realty Trust and Rudin Management Co. to master lease a new $1.2 billion, 1,500 feet (460 m) office tower to be constructed on Park Avenue in Midtown Manhattan to serve as Citadel's new New York City headquarters to solidify access to deep pools of global capital as well as connectivity with Asian clientele.
In 2022, Citadel's hedge fund unit posted its record year of revenues to date, generating about $28 billion in revenue. Citadel returned $16 billion to its clients in 2022, which was a record annual return for both the fund of American investor Kenneth Griffin and the entire industry. In addition, this allowed Citadel to overtake Bridgewater in the list of the most profitable hedge funds in history according to experts from LCH Investments.
In 2023, Citadel returned about $7 billion in profits to its clients, which amounted to about a 15% return for its flagship fund.
In June 2024, Citadel agreed to purchase Japanese power company Energy Grid. The transaction was the first major US investment in Japan's wholesale energy market in the past few years.
As of June 2024, Citadel managed more than $63 billion in capital and was one of the world's largest asset managers. In 2023 Citadel was ranked the second largest multi-strategy hedge fund globally. Citadel's group of hedge funds rank among the largest and most successful hedge funds in the world.
In March 2025, Citadel purchased Paloma Natural Gas (now Apex Natural Gas) for about $1 billion.
In September 2025, Citadel announced it would take office space atop Boston's new South Station Tower.
In October 2025, Citadel LLC announced it would acquire German power trading firm, FlexPower.
In October 2025, Citadel agreed to acquire FlexPower, a Hamburg-based renewable energy trading firm founded in 2022 that specializes in trading and risk management solutions across six European countries. It manages over 1,700 megawatts of power capacity. The acquisition, the terms of which were not disclosed, was part of Citadel's broader expansion in the global energy and commodities markets and followed the earlier acquisition of Paloma Natural Gas LLC in the United States.
Citadel's assets under management (AUM) increased to $67 billion at the start of 2026, and they returned approximately $5 billion to investors.
From Wikipedia’s article on Citadel LLC, shared under CC BY-SA 4.0.5