Ken Griffin, head of the massive hedge fund Citadel Advisors, made significant changes to the fund's investment portfolio in the first quarter of 2026, as revealed in the 13F filing published on March 31, 2026. Citadel initiated a new position in AstraZeneca PLC ($AZN) valued at $519 million, and also a new position in Pinnacle Finl Partners Inc. ($PNFP) valued at $285 million.

Alongside these new positions, the fund sold its entire holdings in Seagate HDD Cayman ($STX), which was valued at $336 million, and Cyberark Software Ltd ($CYBR), valued at $331 million. These moves indicate Griffin's renewed preference for the healthcare and financial sectors, while reducing exposure to data storage and cybersecurity.

For individual traders, Ken Griffin's and Citadel's moves offer insight into how big money manages risk and seeks opportunities across different sectors. Citadel is known for its sophisticated and diverse trading strategies, and these changes could reflect a re-evaluation of market conditions and growth opportunities. It is important to remember that 13F filings reflect the portfolio's status at the end of the quarter (in this case, March 31, 2026) and do not represent real-time transactions. The fund may have made further changes since the reporting date.