HEIDEN WILLIAM K
SEC insider (Form 3/4/5 filer). CIK 0001214939. Director at Atara Biotherapeutics, Inc. (ATRA) and 1 other issuer. 10 reported Form 4/5 transactions since Sep 2024; latest on Jun 9, 2026. Located in THOUSAND OAKS, CA.
Companies HEIDEN WILLIAM K has filed insider reports for
- Atara Biotherapeutics, Inc. (ATRA): Director
- MACROGENICS INC (MGNX): Director
HEIDEN WILLIAM K
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.
AwardDirect12K shares- - May 19, 2026MGNX
MACROGENICS INC
AwardDirectRestricted Stock Unit
3.8K shares- - May 19, 2026MGNX
MACROGENICS INC
AwardDirectStock Option (right to buy)
22K shares- - May 18, 2026MGNX
MACROGENICS INC
ExerciseDirect3.8K shares- - Aug 20, 2025MGNX
MACROGENICS INC
PurchaseDirect49.5K shares at avg. $1.49$74K - Aug 19, 2025MGNX
MACROGENICS INC
PurchaseDirect50.5K shares at avg. $1.52$77K - Jun 10, 2025ATRA
Atara Biotherapeutics, Inc.
AwardDirect7.8K shares- - May 21, 2025MGNX
MACROGENICS INC
AwardDirectStock Option (right to buy)
22K shares- - May 21, 2025MGNX
MACROGENICS INC
AwardDirectRestricted Stock Unit
3.8K shares- - May 20, 2025MGNX
MACROGENICS INC
ExerciseDirect6.5K shares-
| Type | Shares | Price | Ownership | |||
|---|---|---|---|---|---|---|
| Jun 9, 2026 |  ATRA Atara Biotherapeutics, Inc. | Award | 12,000 | - | $0 | Direct |
| May 19, 2026 |  MGNX MACROGENICS INC | Award Restricted Stock Unit | 3,750 | - | - | Direct |
| May 19, 2026 | MGNX MACROGENICS INC | Award Stock Option (right to buy) | 22,000 | - | - | Direct |
| May 18, 2026 | MGNX MACROGENICS INC | Exercise | 3,750 | - | $0 | Direct |
| Aug 20, 2025 | MGNX MACROGENICS INC | Purchase | 49,500 | $1.49 | $73,755 | Direct |
| Aug 19, 2025 | MGNX MACROGENICS INC | Purchase | 50,500 | $1.52 | $76,760 | Direct |
| Jun 10, 2025 | ATRA Atara Biotherapeutics, Inc. | Award | 7,828 | - | - | Direct |
| May 21, 2025 | MGNX MACROGENICS INC | Award Stock Option (right to buy) | 22,000 | - | - | Direct |
| May 21, 2025 | MGNX MACROGENICS INC | Award Restricted Stock Unit | 3,750 | - | - | Direct |
| May 20, 2025 | MGNX MACROGENICS INC | Exercise | 6,500 | - | - | Direct |
1-10 of 10 transactions