Vadym Hassieiev

Ukrainian mathematics olympiad competitor; represented Ukraine at the International Mathematical Olympiad 2022 (bronze medal, 25 points), a student at Lycee Louis-le-Grand in Paris after being displaced from Kharkiv by the war on 2022-02-24.

Notes9

• Quant employment verification: UNRESOLVED. The only evidence for a Citadel Securities role is a LinkedIn-derived index record (index lists 'Student Researcher at Citadel Securities', Jul-Sep 2023) carried by both the caller-supplied taiga lead and the profile-index enrichment - not independent primary confirmation. His public LinkedIn headline reads 'Mathematics Graduate | ... | IMO', and a search snippet shows a connection to 1 person at Citadel Securities, but no accessible primary page states the role, dates, or team. A distinct second LinkedIn account ('Student at University of Cambridge') lists no Citadel role. Citadel Securities is a genuine quantitative market-maker (citadelsecurities.com, securities trading/market-making), so the employer classifies as quantitative finance; the KM3Net role is a neutrino-astrophysics research internship, not finance. Because the role is index-only and the two LinkedIn records conflict on it, employment in quantitative finance is not independently confirmed.Sep 17, 2026
• Index-only (not primary): the profile index records a 'Student Researcher' stint at Citadel Securities, Jul-Sep 2023 (2023-07 to 2023-09).Jul 2023
• Two LinkedIn slugs appear for the same name and both list University of Cambridge: .../vadym-hassieiev-538695245 (Mathematics Graduate, location Poland, ex-KM3Net, ex-Citadel Securities) and .../vadym-hassieiev-83967425b (Student at University of Cambridge, education Kharkiv Physics & Mathematics Lyceum No. 27); the shared Cambridge tie plus the Lyceum-27-to-Paris trajectory indicate one person with two accounts, but this is not primary-confirmed.
• Displaced from Kharkiv by the war on 2022-02-24 and continued his studies in preparatory classes (CPGE) at Lycee Louis-le-Grand in Paris from September 2022, supported by IHES at the initiative of CNRS research director Ahmed Abbes.
• Won a bronze medal for Ukraine at IMO 2022 (25 points, rank 230, 61.1%).
• Completed a Data Science internship at KM3Net, the KM3NeT neutrino-telescope research collaboration - a research rather than finance role; the profile index lists his headline skills as 'C++, Python, SQL'.
• Silver medal at the International Zhautykov Olympiad (IZhO) 2022 in Kazakhstan; represented Junior Karazin University, Kharkiv.
• Honourable mention at the Romanian Masters of Mathematics (RMM) 2021.
• Gold medal at the All-Ukrainian Team Programming Olympiad; also interested in computer programming.
• Served as a Coordinator on EGMO 2024 (Georgia) staff - a role organizing the girls' olympiad rather than competing.
• Participated in the Ukrainian Olympiad in Informatics (UOI) 2021, recorded at data.uoi.ua under full name Hassieiev Vadym Semenovych.
• Before the war he was a final-year student at Kharkiv Physics and Mathematics Lyceum No. 27 and volunteered organizing mathematics competitions in Kharkiv.