Unheimlich interessant und beängstigend zugleich, wenn man sich den englischen Wiki-Artikel zu Citadel durchliest. Wer danach noch denkt, dass es hier rechtschaffend vor sich geht .....
Hier die aus meiner Sicht interessanteste Passage zu Citadel Securities (gehört neben Citadel LLC ebenfalls zu 85% Kenny, nach dem Motto "Alles aus einer Hand") mal als Text reinkopiert. Nach zu lesen auch unter: https://en.m.wikipedia.org/wiki/Citadel_LLC
sorry für das Gro an Text, aber ich halte es für ein Stück Allgemeinbildung. Viel Spaß beim Lesen und setzt euch besser hin :-)
Citadel Securities is the largest market maker in options in the U.S., executing about 25 percent of U.S.-listed equity options volume.[
Over a two-year period until September 2014, hundreds of thousands of large OTC orders were removed from its automated trading processes, rendering the orders "inactive" so that they had to be handled manually by human traders. Citadel Securities then "traded for its own account on the same side of the market at prices that would have satisfied the orders," without immediately filling the inactive orders at the same or better prices as required by FINRA rules.
In 2014, Citadel was fined $800,000 for irregularities in its trading practices between March 18, 2010, and Jan. 8, 2013 
In 2017, Citadel was fined $22 million by the SEC for misleading clients regarding the way it priced trades.
In 2018, Citadel was forced by the SEC to pay $3.5 million over violations stemming from incorrect reporting for nearly 80 million trades from 2012 to 2016.
In 2018, Bloomberg reported that 40% of Robinhood's revenues were derived from selling customer orders to firms such as Citadel Securities and Two Sigma Securities.
In January 2020, Citadel paid a 670 million-yuan ($97 million) settlement for alleged trading irregularities dating from 2015.
Citadel Securities was fined $700,000 by FINRA in July 2020 for trading ahead of customer orders. They delayed certain equity orders from clients to buy or sell shares while continuing to trade the same stocks in its own account as part of its market-making activities, according to FINRA.
In 2020, Citadel Securities was censured by FINRA a total of 19 times for a variety of misconduct, including failing to close failure-to-deliver positions, naked short selling, inaccurate reporting of short sale indicators, executing trades during circuit-breaker halts, and failing to offer its clients best prices on the bid-ask spread.
On March 25, 2021, Citadel agreed to a censure by FINRA and a $275,000 fine for improperly reporting nearly 500,000 Treasury transactions between 2017 and 2019, revealing a systemic failure in Citadel's compliance systems.
Concerns about conflicts of interest
In light of Citadel Securities's role in the GameStop short squeeze event, individuals such as Senator Elizabeth Warren have raised concerns about several potential conflicts of interest. These include the relationship between Citadel Securities, which executes a majority of broker-dealer Robinhood's trades through a payment-for-order-flow relationship, and Citadel the asset manager, which provided a $2 billion investment in Melvin Capital, one of the main short sellers involved in the GameStop short squeeze; because Ken Griffin, the CEO and majority shareholder of Citadel, also owns 85% of Citadel Securities, there are concerns that the market maker's interests might align with the interests of those shorting GameStop to the detriment of those long GameStop. Griffin has denied any wrongdoing.
On March 17, 2021 Citadel's payment-for-order-flow arrangements with brokerages such as Robinhood was heavily criticized during Congressional hearings on the GameStop short squeeze.
Citadel's practice of hiring officials from agencies that regulate it, including the SEC and the CFTC, as well its relationships with Ben Bernanke and Janet Yellen, has also been widely observed and attracted concerns about conflicts of interest.
Concerns about systemic risk posed to U.S. markets
Analysts of U.S. financial markets have been critical of the SEC's decision to exclude Citadel Securities from its 2014 Regulation Systems Compliance and Integrity (Reg SCI) regulatory regime designed to make U.S securities markets safer for investors; both Citadel and the SEC declined to comment on Citadel's being exempted from complying with this rule.
On February 17, 2021, House Financial Services Chairwoman Maxine Waters suggested that the systematic importance of Citadel Securities might ultimately pose a threat to the U.S. financial system. This point also emerged on several occasions during the March 17, 2021 hearing by the House Financial Services, with experts observing that Citadel Securities claims to trade "approximately 26% of U.S. equities volume" and "executes approximately 47% of all U.S.-listed retail volume, and acts as a specialist or market-maker with respect to 99% of traded volume in 3,000 U.S.-listed options names."
In March 2021, President Biden's nominee for SEC Chairman, Gary Gensler, raised further concerns about Citadel's dominant market position in at a Congressional hearing in March 2021, asking: “one firm now has 40% to 50% of the retail order flow, what does that do to pricing of capital in this country? What does it mean to be best execution in this context?” Invoking Amazon's dominance in the online retail marketplace, another market analyst described Citadel's rise as “the Amazonization of listed markets", a phenomenon he characterized as “very dangerous, not because there are no other players, but because over time it weakens the other players that could be competitive. It’s the essence of concentration risk.”