Key Takeaways
- • Citadel Securities is executing a targeted hiring campaign in New York, recruiting senior technology and trading talent from competing elite firms including Two Sigma and Millennium Management.
- • Mark Beningo joined as a derivatives trader from Chicago Trading Company, bringing 13 years of experience at Hong Kong-based high-frequency trading firm Volant Trading and prior tenure in UBS's equity derivatives electronic market-making unit.
- • Triantafyllos Alexiou and Kyuwon Choi joined as software engineers—Alexiou from Millennium (11 years) with prior experience leading Citi's delta one trading system, and Choi from Two Sigma (4 years) with previous roles at Bloomberg and Perella Weinberg Partners.
- • All three hires occurred on the same date (January 8, 2025), signaling a coordinated recruitment push aligned with Citadel Securities' broader 2025 hiring expansion alongside parent company Citadel's hedge fund operations.
Summary
Citadel Securities, the electronic trading subsidiary of Citadel hedge fund, is aggressively recruiting senior talent from institutional investment firms and high-frequency trading competitors in its New York office. The firm brought in three key personnel simultaneously on January 8, 2025, targeting quantitative traders and software engineers with deep experience in derivatives markets and trading infrastructure.
Mark Beningo joined Citadel Securities as a derivatives trader after three years as a senior quant trader at Chicago Trading Company, a high-frequency trading firm. His career trajectory reflects deep expertise in electronic market-making: Beningo spent 13 years at Volant Trading, a Hong Kong-based HFT operation, and previously worked within UBS's equity derivatives electronic market-making team. His appointment targets Citadel Securities' derivatives trading operations and signals the firm's focus on recruiting experienced quant traders from the HFT sector.
The firm also hired two software engineers to bolster its technology infrastructure. Triantafyllos Alexiou, recruited from Millennium Management, spent 11 years as a software engineer at the $79 billion hedge fund and previously served as global order management system lead for Citi's delta one trading team. Kyuwon Choi joined Citadel Securities' execution services team after four years at Two Sigma; his background includes senior engineering roles at Bloomberg and early-career experience as a quant researcher in the global macro fund at Perella Weinberg Partners.
The simultaneous hiring of these three professionals reflects Citadel Securities' capacity-building in 2025, consistent with parallel hiring activity at Citadel hedge fund. The recruitment specifically targets elite competitors—Two Sigma and Millennium Management are among the industry's most sophisticated quantitative and technology-focused institutions—indicating Citadel Securities is prioritizing infrastructure and derivatives capabilities. Citadel Securities declined to comment on the hires.
Mark Beningo joined Citadel Securities as a derivatives trader after three years as a senior quant trader at Chicago Trading Company, a high-frequency trading firm. His career trajectory reflects deep expertise in electronic market-making: Beningo spent 13 years at Volant Trading, a Hong Kong-based HFT operation, and previously worked within UBS's equity derivatives electronic market-making team. His appointment targets Citadel Securities' derivatives trading operations and signals the firm's focus on recruiting experienced quant traders from the HFT sector.
The firm also hired two software engineers to bolster its technology infrastructure. Triantafyllos Alexiou, recruited from Millennium Management, spent 11 years as a software engineer at the $79 billion hedge fund and previously served as global order management system lead for Citi's delta one trading team. Kyuwon Choi joined Citadel Securities' execution services team after four years at Two Sigma; his background includes senior engineering roles at Bloomberg and early-career experience as a quant researcher in the global macro fund at Perella Weinberg Partners.
The simultaneous hiring of these three professionals reflects Citadel Securities' capacity-building in 2025, consistent with parallel hiring activity at Citadel hedge fund. The recruitment specifically targets elite competitors—Two Sigma and Millennium Management are among the industry's most sophisticated quantitative and technology-focused institutions—indicating Citadel Securities is prioritizing infrastructure and derivatives capabilities. Citadel Securities declined to comment on the hires.
Go deeper than the headline
Research every firm in this story, track the ones that matter and get the daily briefing — free for 7 days.