JANA Partners Management, LP is an institutional investment manager that files quarterly 13F reports with the SEC. As of Q4 2025, the fund manages $1.9B in reported equity holdings across 12 positions. The largest holdings are MRCY (18.8%), COO (15.0%), SPY (13.9%), LW (10.9%), MKL (9.1%). The portfolio is concentrated in Other (77.8%), Healthcare (15.0%), Consumer Defensive (7.2%). Data sourced from SEC EDGAR 13F filings (CIK 1998597).