HEIDEN WILLIAM K

Director · ATRA, MGNX

As of 2026-09-16, HEIDEN WILLIAM K has 14 Form 4 transactions on record across 2 companies — 6 in the trailing 12 months.

Everything this person has disclosed to the SEC on Form 4 — across every company they file for — reconstructed from the public record. A filing history, not a tip sheet.

Reconstructed holdings

Direct: $435KIndirect: $0$435Kas of 2026-09-16
  • Direct $435K
  • Indirect $0
ATRAdirect34,188 sh$346K
MGNXdirect22,000 sh$90K

Reconstructed from this person's own Form 4 filings — the total each filing reported owning afterward, priced at the close on the as-of date shown. A filed position can lag the real one.

Direct and indirect holdings (e.g. through a trust or fund) are tagged separately, as filed.

Trades by company

MGNX · 12 trades
2026-05-19: Award / grant, 22,000 sh ($0)2026-05-19: Award / grant, 3,750 sh ($0)2026-05-18: Option exercise, 3,750 sh ($0)2026-05-18: Option exercise, 3,750 sh2026-05-18: Option exercise, 3,750 sh2025-08-20: Purchase, 49,500 sh ($74K)2025-08-19: Purchase, 50,500 sh ($77K)2025-05-21: Award / grant, 22,000 sh ($0)2025-05-21: Award / grant, 3,750 sh ($0)2025-05-20: Option exercise, 6,500 sh ($0)2025-05-20: Option exercise, 6,500 sh2025-05-20: Option exercise, 6,500 sh
ATRA · 2 trades
2026-06-09: Award / grant, 12,000 sh ($0)2025-06-10: Award / grant, 7,828 sh ($0)

Filing ledger

DateCompanyActionShares @ priceValueOwnership ΔOwned afterFiling
2025-08-20MGNXPurchase49,500 @ $1.49$74K+80.5% of holding111,000Form 4
2025-08-19MGNXPurchase50,500 @ $1.52$77K+459.1% of holding61,500Form 4
12 award / exercise / gift records — not counted as purchases
DateCompanyActionSharesOwned afterFiling
2026-06-09ATRAAward / grant12,00034,188Form 4
2026-05-19MGNXAward / grant22,00022,000Form 4
2026-05-19MGNXAward / grant3,7503,750Form 4
2026-05-18MGNXOption exercise3,7500Form 4
2026-05-18MGNXOption exercise3,750114,750Form 4
2026-05-18MGNXOption exercise3,750114,750Form 4
2025-06-10ATRAAward / grant7,82822,188Form 4
2025-05-21MGNXAward / grant22,00022,000Form 4
2025-05-21MGNXAward / grant3,7503,750Form 4
2025-05-20MGNXOption exercise6,5000Form 4
2025-05-20MGNXOption exercise6,50011,000Form 4
2025-05-20MGNXOption exercise6,50011,000Form 4

Source: SEC Form 4 filings. Each row links to its original filing.

Research tool, not investment advice — historical frequencies, not recommendations. A product of Marovel Technologies LLC. Full terms.