William K. Heiden
CIK: 0001214939
Transaction Breakdown
High conviction signal
Position reduction
Derivative conversions
Compensation grants
Gifts, tax withholding, conversions, dispositions to the issuer and other codes
Discretionary Trading P&L
Holdings
Transaction History (10 total)
- Jun 9, 2026ATRA
Atara Biotherapeutics, Inc.
Award(A)Direct12K shares- - May 19, 2026MGNX
MACROGENICS INC
Award(A)DirectRestricted Stock Unit
3.8K shares- - May 19, 2026MGNX
MACROGENICS INC
Award(A)DirectStock Option (right to buy)
22K shares- - May 18, 2026MGNX
MACROGENICS INC
Exercise(M)Direct3.8K shares- - Aug 20, 2025MGNX
MACROGENICS INC
Purchase(P)Direct49.5K shares at avg. $1.49$74K - Aug 19, 2025MGNX
MACROGENICS INC
Purchase(P)Direct50.5K shares at avg. $1.52$77K - Jun 10, 2025ATRA
Atara Biotherapeutics, Inc.
Award(A)Direct7.8K shares- - May 21, 2025MGNX
MACROGENICS INC
Award(A)DirectStock Option (right to buy)
22K shares- - May 21, 2025MGNX
MACROGENICS INC
Award(A)DirectRestricted Stock Unit
3.8K shares- - May 20, 2025MGNX
MACROGENICS INC
Exercise(M)Direct6.5K shares-
| Type | Shares | Price | Ownership | |||
|---|---|---|---|---|---|---|
| Jun 9, 2026 |  ATRA Atara Biotherapeutics, Inc. | Award(A) | 12,000 | - | $0 | Direct |
| May 19, 2026 |  MGNX MACROGENICS INC | Award(A) Restricted Stock Unit | 3,750 | - | - | Direct |
| May 19, 2026 | MGNX MACROGENICS INC | Award(A) Stock Option (right to buy) | 22,000 | - | - | Direct |
| May 18, 2026 | MGNX MACROGENICS INC | Exercise(M) | 3,750 | - | $0 | Direct |
| Aug 20, 2025 | MGNX MACROGENICS INC | Purchase(P) | 49,500 | $1.49 | $73,755 | Direct |
| Aug 19, 2025 | MGNX MACROGENICS INC | Purchase(P) | 50,500 | $1.52 | $76,760 | Direct |
| Jun 10, 2025 | ATRA Atara Biotherapeutics, Inc. | Award(A) | 7,828 | - | - | Direct |
| May 21, 2025 | MGNX MACROGENICS INC | Award(A) Stock Option (right to buy) | 22,000 | - | - | Direct |
| May 21, 2025 | MGNX MACROGENICS INC | Award(A) Restricted Stock Unit | 3,750 | - | - | Direct |
| May 20, 2025 | MGNX MACROGENICS INC | Exercise(M) | 6,500 | - | - | Direct |
1-10 of 10 transactions
About HEIDEN WILLIAM K
HEIDEN WILLIAM K (SEC CIK 0001214939) files insider reports with the SEC as Director of Atara Biotherapeutics, Inc. (ATRA) and Director of MACROGENICS INC (MGNX).
Signal8 holds 5 ownership filings by HEIDEN WILLIAM K, all Form 4s, filed between May 22, 2025 and Jun 11, 2026. Those filings report 10 transactions, from May 20, 2025 to Jun 9, 2026. Signal8's Form 4 history starts in Sep 2024.
The business address on HEIDEN WILLIAM K's filings is in THOUSAND OAKS, CA.
Recent filings by HEIDEN WILLIAM K
- Jun 9, 2026: Grant or award of ATRA shares (Form 4, code A).
- May 19, 2026: Grants or awards of MGNX derivative securities (2 lines, Form 4, code A).
- May 18, 2026: Option exercise of MGNX shares (Form 4, code M).
- Aug 20, 2025: Open-market purchase of MGNX shares (Form 4, code P).
- Aug 19, 2025: Open-market purchase of MGNX shares (Form 4, code P).
Other insiders filing for Atara Biotherapeutics, Inc. (ATRA)
- Cherry Brian N, Director
- Nguyen AnhCo, President and CEO
- Redmile Group, LLC, Director
- Sarney Kevin G, Interim CFO
- Fust Matthew K, Director
- Ciongoli Gregory Austin, Director