William K. Heiden

Companies

• MACROGENICS INCBoard member May 24, 2022 to now¹
• Atara Biotherapeutics, Inc.Board member Nov 25, 2015 to now²
• AMAG PharmaceuticalsBoard member May 16, 2012 to Mar 4, 2020³
• AMAG PharmaceuticalsChief executive officer May 16, 2012 to Mar 4, 2020³
• AMAG PharmaceuticalsPresident May 16, 2012 to Mar 4, 2020³

Holdings

Stock this person has reported owning, from the forms officers and directors file with the SEC. See the biggest insider stakes.

Shares held

• MMACROGENICS INC MGNX114,750 shares⁴$382.7K at $3.33May 18, 2026
• ABAtara Biotherapeutics, Inc. ATRA34,188 shares⁵$315.9K at $9.24Jun 9, 2026

As of each latest filing. The line shows shares held over time.

Recent filings

• Jun 9, 2026Granted 12,000 shares of Atara Biotherapeutics, Inc.⁵
• May 18, 2026Exercised options 3,750 shares of MACROGENICS INC⁴
• Aug 20, 2025Bought 49,500 shares at $1.49 of MACROGENICS INC⁶
• Aug 19, 2025Bought 50,500 shares at $1.52 of MACROGENICS INC⁶
• Jun 10, 2025Granted 7,828 shares of Atara Biotherapeutics, Inc.⁷
• May 20, 2025Exercised options 6,500 shares of MACROGENICS INC⁸
• May 20, 2024Exercised options 4,500 shares of MACROGENICS INC⁹
• Mar 31, 2024Granted 150,000 shares of Atara Biotherapeutics, Inc.¹⁰
• Nov 10, 2023Bought 100,000 shares at $0.25 of Atara Biotherapeutics, Inc.¹¹
• May 31, 2023Granted 57,000 shares of Atara Biotherapeutics, Inc.¹²
• Jun 23, 2022Granted 20,500 shares of Atara Biotherapeutics, Inc.¹³