Citadel Executive and Leadership Team

Fallon Sullivan, the Chief Administrative Officer & Chief Executive Officer, Office of at Citadel, directs the overarching administrative framework and executive governance. Sullivan manages the internal infrastructure required to support complex IT service delivery models. By aligning administrative policies with the broader corporate mission, the Chief Administrative Officer & Chief Executive Officer, Office of ensures that all departments operate with maximum efficiency. This leadership role involves coordinating high-level strategic initiatives that span the entire organization. Fallon Sullivan maintains rigorous standards for operational integrity, facilitating seamless communication between the executive suite and functional teams. Through the implementation of robust management protocols, the Chief Administrative Officer & Chief Executive Officer, Office of drives the firm toward sustainable growth. Sullivan oversees the integration of innovative practices into daily administrative workflows, ensuring that the company remains at the forefront of the technology consulting industry while providing consistent value to clients across diverse global markets.

Isabella Bondarev, the Chief Operating Officer Team, Office of the Chief Financial Officer at Citadel, manages the operational efficiency of financial reporting and resource allocation. Bondarev directs the integration of financial data systems with the firm's broader IT strategy. By overseeing the coordination between the finance department and technical teams, the Chief Operating Officer Team, Office of the Chief Financial Officer ensures that financial operations remain transparent and accurate. This leadership role involves driving the adoption of advanced analytical tools to improve budgeting and forecasting. Isabella Bondarev collaborates with the Chief Financial Officer to align financial goals with the company's long-term growth objectives. Through the optimization of financial workflows, the Chief Operating Officer Team, Office of the Chief Financial Officer supports the firm's ability to invest in innovative IT services. Bondarev focuses on maintaining rigorous financial controls, ensuring that all operational activities contribute to the company's overall financial health and market stability.

Srimouli Nalluri, the Chief Operating Officer, Electronic Trading Engineering at Citadel, manages the operational efficiency of electronic trading systems. Nalluri directs the engineering teams responsible for building high-frequency, low-latency platforms that define the firm's market presence. By overseeing the technical architecture of trading environments, the Chief Operating Officer, Electronic Trading Engineering ensures that all systems meet the highest standards of reliability and performance. This leadership role involves close collaboration with risk management and infrastructure teams to maintain seamless operations. Srimouli Nalluri drives the development of innovative trading tools that support the company's complex IT service model. Through the continuous refinement of engineering processes, the Chief Operating Officer, Electronic Trading Engineering optimizes system throughput and stability. Nalluri focuses on scaling these platforms to handle increasing market demands, ensuring that the firm remains a leader in electronic trading technology. The Chief Operating Officer, Electronic Trading Engineering maintains a strategic focus on technical excellence and operational precision.

Zachary Flum, the Chief Operating Officer, Eqr Research & Platform Engineering at Citadel, leads the operational strategy for equity research and core platform engineering. Flum directs the integration of research-driven insights into the company's proprietary technology platforms. By overseeing the alignment between research objectives and engineering execution, the Chief Operating Officer, Eqr Research & Platform Engineering ensures that the firm delivers cutting-edge analytical tools. This leadership role involves managing cross-functional teams to accelerate the deployment of new platform features. Zachary Flum drives the development of robust databases and analytical frameworks that support the company's IT service offerings. Through the optimization of research workflows, the Chief Operating Officer, Eqr Research & Platform Engineering enhances the firm's ability to provide actionable intelligence to clients. Flum focuses on maintaining high operational standards across all engineering projects, ensuring that the platform remains scalable and secure. The Chief Operating Officer, Eqr Research & Platform Engineering supports the firm's growth through continuous technical innovation.

John Niccolai, the Chief Operating Officer, Global Fixed Income at Citadel, manages the operational infrastructure supporting global fixed income activities. Niccolai directs the implementation of specialized IT services tailored to the unique requirements of fixed income markets. By overseeing the coordination between trading desks and technical support teams, the Chief Operating Officer, Global Fixed Income ensures that all operations remain efficient and compliant. This leadership role involves driving the adoption of new technologies that improve trade execution and risk management. John Niccolai collaborates with global stakeholders to ensure that the firm's fixed income platforms remain competitive and reliable. Through the optimization of operational workflows, the Chief Operating Officer, Global Fixed Income supports the firm's broader mission of delivering high-quality IT solutions. Niccolai focuses on building resilient systems that can withstand volatile market conditions, ensuring consistent service delivery. The Chief Operating Officer, Global Fixed Income maintains a strategic focus on operational excellence and technical integration.

Antonia Peabody, the Senior Deputy General Counsel & Chief Operating Officer, Legal & Compliance at Citadel, oversees the operational framework for legal and regulatory compliance. Peabody directs the integration of compliance protocols into the firm's IT service delivery models. By managing the intersection of legal requirements and technical operations, the Senior Deputy General Counsel & Chief Operating Officer, Legal & Compliance ensures that all business activities adhere to global standards. This leadership role involves coordinating with internal teams to mitigate risk and maintain organizational integrity. Antonia Peabody drives the development of automated compliance tools that streamline regulatory reporting and monitoring. Through the implementation of robust legal frameworks, the Senior Deputy General Counsel & Chief Operating Officer, Legal & Compliance supports the firm's commitment to ethical business practices. Peabody focuses on building a culture of compliance that permeates all technical and operational functions, ensuring that the company remains a trusted partner in the technology consulting industry.

Tom Booker, the Chief Operating Officer, Portfolio Construction & Risk Engineering at Citadel, leads the operational strategy for portfolio construction and risk management systems. Booker directs the engineering teams responsible for building sophisticated risk assessment models. By overseeing the integration of these models into the firm's IT service platforms, the Chief Operating Officer, Portfolio Construction & Risk Engineering ensures that clients receive accurate and timely risk insights. This leadership role involves managing the development of high-performance computing resources that support complex portfolio analysis. Tom Booker drives the adoption of innovative risk engineering practices that enhance the firm's competitive position. Through the optimization of data processing workflows, the Chief Operating Officer, Portfolio Construction & Risk Engineering improves the speed and reliability of risk reporting. Booker focuses on building scalable systems that can handle large-scale data sets, ensuring that the firm remains at the forefront of risk management technology and service delivery.

Laurie Haning, the Chief Operating Officer, Finance & Accounting at Citadel, manages the operational infrastructure for all finance and accounting functions. Haning directs the implementation of automated accounting systems that support the firm's IT service delivery. By overseeing the coordination between finance teams and technical support, the Chief Operating Officer, Finance & Accounting ensures that all financial processes are efficient and compliant. This leadership role involves driving the adoption of new technologies that improve financial transparency and reporting accuracy. Laurie Haning collaborates with other C-suite leaders to ensure that financial resources are allocated effectively to support strategic initiatives. Through the optimization of accounting workflows, the Chief Operating Officer, Finance & Accounting supports the firm's broader mission of delivering high-quality IT solutions. Haning focuses on building resilient financial systems that can support the company's global operations, ensuring that the firm maintains a strong financial foundation while continuing to innovate in the technology consulting space.

Janna Shaftan, the Chief Operating Officer, Platform Engineering (Ai, Databases, China) at Citadel, manages the operational strategy for AI, database infrastructure, and regional operations in China. Shaftan directs the engineering teams responsible for building scalable AI and database platforms that support the firm's global IT services. By overseeing the integration of these technologies into the company's core offerings, the Chief Operating Officer, Platform Engineering (Ai, Databases, China) ensures that the firm remains a leader in technical innovation. This leadership role involves coordinating cross-functional teams to deploy advanced AI solutions across diverse markets. Janna Shaftan drives the development of robust database architectures that ensure data integrity and performance. Through the optimization of engineering processes, the Chief Operating Officer, Platform Engineering (Ai, Databases, China) enhances the firm's ability to deliver high-performance IT solutions. Shaftan focuses on building a strong technical presence in the region, ensuring that the company's platform engineering capabilities remain at the cutting edge of the industry.

Stephen Youtzy, the Chief Technology Officer at Citadel, architects the technical vision and innovation roadmap for the entire organization. Youtzy oversees the development of advanced IT service platforms, ensuring that all technological solutions align with the company's commitment to integrity and excellence. By managing the engineering teams, the Chief Technology Officer drives the creation of scalable, secure, and high-performance systems. This leadership role requires constant evaluation of emerging technologies to maintain a competitive edge in the global market. Stephen Youtzy collaborates with other C-suite leaders to integrate these technical advancements into the broader business strategy. Through the optimization of internal development cycles, the Chief Technology Officer ensures that client support remains stellar and responsive. Youtzy focuses on building resilient infrastructure that supports 24/7 operations, directly impacting the firm's ability to deliver reliable IT services. The Chief Technology Officer maintains a clear focus on long-term technical sustainability and innovation.