The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
| Date | Insider | Role | Action | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Mar 2, 2026 | Henson Heidi | Director | Grant(A) | 50K | — | $0 |
| Mar 2, 2026 | Hunt Jonathan Robert | Chief Accounting Officer | Grant(A) | 90K | — | $0 |
| Mar 2, 2026 | Woods Lori A | Director | Grant(A) | 50K | — | $0 |
| Mar 2, 2026 | Williamson Robert F III | Director | Grant(A) | 50K | — | $0 |
| Mar 2, 2026 | Spoor Johan M. | Chief Executive Officer, Director | Grant(A) | 735K | — | $0 |
| Mar 2, 2026 | Morich Frank | Director | Grant(A) | 50K | — | $0 |
| Mar 2, 2026 | Martinez Maria E | Director | Grant(A) | 50K | — | $0 |
| Mar 2, 2026 | Puhlmann Markus | Chief Medical Officer | Grant(A) | 150K | — | $0 |
| Nov 13, 2025 | Hunt Jonathan Robert | Chief Accounting Officer | Buy(P) | 11K | $2.03 | $22K |
| Nov 12, 2025 | Williamson Robert F III | Director | Buy(P) | 9K | $2.10 | $20K |
| Sep 4, 2025 | Sendek Joel | Chief Financial Officer | Grant(A) | 600K | — | $0 |
| Sep 3, 2025 | Martinez Maria E | Director | Grant(A) | 75K | — | $0 |
| Mar 31, 2025 | Woods Lori A | Director | Buy(P) | 23K | $2.13 | $50K |
| Mar 31, 2025 | Williamson Robert F III | Director | Buy(P) | 38K | $2.14 | $82K |
| Mar 28, 2025 | Graham Juan | Chief Financial Officer | Buy(P) | 33K | $2.25 | $75K |
| Mar 28, 2025 | Williamson Robert F III | Director | Buy(P) | 22K | $2.27 | $50K |
| Mar 28, 2025 | Spoor Johan M. | Chief Executive Officer, Director | Buy(P) | 5K | $2.21 | $10K |
| Mar 28, 2025 | Spoor Johan M. | Chief Executive Officer, Director | Buy(P) | 22K | $2.24 | $49K |
| Mar 3, 2025 | Woods Lori A | Director | Grant(A) | 50K | — | $0 |
| Mar 3, 2025 | Morich Frank | Director | Grant(A) | 50K | — | $0 |
| Mar 3, 2025 | Williamson Robert F III | Director | Grant(A) | 50K | — | $0 |
| Mar 3, 2025 | Henson Heidi | Director | Grant(A) | 50K | — | $0 |
| Mar 3, 2025 | Spoor Johan M. | Chief Executive Officer, Director | Grant(A) | 650K | — | $0 |
| Mar 3, 2025 | Hunt Jonathan Robert | Chief Accounting Officer | Grant(A) | 75K | — | $0 |
| Mar 3, 2025 | Puhlmann Markus | Chief Medical Officer | Grant(A) | 165K | — | $0 |
| Jan 6, 2025 | Graham Juan | Chief Financial Officer | Grant(A) | 400K | — | $0 |
| Dec 4, 2024 | Spoor Johan M. | CEO, Director | Buy(P) | 8K | $3.77 | $30K |
| Dec 4, 2024 | Henson Heidi | Director | Buy(P) | 26K | $3.85 | $100K |
| Nov 25, 2024 | Spoor Johan M. | CEO, Director | Buy(P) | 7K | $3.80 | $25K |
| Nov 25, 2024 | Spoor Johan M. | CEO, Director | Buy(P) | 15K | $3.78 | $55K |
| Nov 25, 2024 | Spoor Johan M. | CEO, Director | Buy(P) | 5K | $3.80 | $21K |
| Nov 25, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 10K | $3.88 | $39K |
| Nov 25, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 2K | $3.60 | $9K |
| Nov 25, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 400 | $3.55 | $1K |
| Nov 25, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 29 | $3.94 | $114 |
| Nov 25, 2024 | Williamson Robert F III | Director | Buy(P) | 4K | $3.62 | $13K |
| Nov 25, 2024 | Williamson Robert F III | Director | Buy(P) | 3K | $3.67 | $10K |
| Jul 17, 2024 | Austin Mark John | VP Finance/Prin Fin&Acct Offic | Grant(A) | 35K | — | $0 |
| Jun 20, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Grant(A) | 100K | — | $0 |
| Jun 20, 2024 | Puhlmann Markus | Chief Medical Officer | Grant(A) | 150K | — | $0 |
| Jun 20, 2024 | Spoor Johan M. | CEO, Director | Grant(A) | 500K | — | $0 |
| Jun 20, 2024 | Henson Heidi | Director | Grant(A) | 23K | — | $0 |
| Jun 20, 2024 | Woods Lori A | Director | Grant(A) | 23K | — | $0 |
| Jun 20, 2024 | Morich Frank | Director | Grant(A) | 23K | — | $0 |
| Jun 20, 2024 | Williamson Robert F III | Director | Grant(A) | 23K | — | $0 |
| Jun 17, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 2K | $9.82 | $18K |
| Jun 14, 2024 | Woods Lori A | Director | Buy(P) | 5K | $10.90 | $49K |
| Jun 14, 2024 | Woods Lori A | Director | Buy(P) | 83 | $10.80 | $896 |
| Jun 13, 2024 | Spoor Johan M. | CEO, Director | Buy(P) | 100K | $1.17 | $117K |
| Jun 3, 2024 | Woods Lori A | Director | Buy(P) | 34K | $1.46 | $50K |
| May 31, 2024 | Williamson Robert F III | Director | Buy(P) | 55K | $1.38 | $76K |
| May 31, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 13K | $1.40 | $18K |
| May 31, 2024 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 12K | $1.40 | $17K |
| May 29, 2024 | Williamson Robert F III | Director | Buy(P) | 11K | $1.32 | $15K |
| May 29, 2024 | Williamson Robert F III | Director | Buy(P) | 19K | $1.34 | $25K |
| Apr 23, 2024 | Austin Mark John | VP Finance/Prin Fin&Acct Offic | Option exercise(M) | 30K | $0.36 | $11K |
| Apr 23, 2024 | Austin Mark John | VP Finance/Prin Fin&Acct Offic | Option exercise(M) | 30K | — | $0 |
| Mar 6, 2024 | Lantheus Alpha Therapy, LLC | 10% Owner | Buy(P) | 60.4M | $0.95 | $57.4M |
| Jan 30, 2024 | Williamson Robert F III | Director | Buy(P) | 43K | $0.72 | $31K |
| Jan 30, 2024 | Williamson Robert F III | Director | Buy(P) | 57K | $0.71 | $41K |
| Jan 30, 2024 | Williamson Robert F III | Director | Buy(P) | 5K | $0.71 | $4K |
| Jan 30, 2024 | Williamson Robert F III | Director | Buy(P) | 19K | $0.71 | $13K |
| Jan 30, 2024 | Williamson Robert F III | Director | Buy(P) | 4K | $0.70 | $2K |
| Jan 29, 2024 | Williamson Robert F III | Director | Buy(P) | 21K | $0.64 | $14K |
| Jan 29, 2024 | Williamson Robert F III | Director | Buy(P) | 4K | $0.64 | $3K |
| Jan 26, 2024 | Williamson Robert F III | Director | Buy(P) | 9K | $0.59 | $5K |
| Jan 26, 2024 | Williamson Robert F III | Director | Buy(P) | 25K | $0.55 | $14K |
| Jan 26, 2024 | Williamson Robert F III | Director | Buy(P) | 50K | $0.54 | $27K |
| Jan 26, 2024 | Williamson Robert F III | Director | Buy(P) | 12K | $0.61 | $7K |
| Jan 26, 2024 | Williamson Robert F III | Director | Buy(P) | 15K | $0.61 | $9K |
| Jan 25, 2024 | Williamson Robert F III | Director | Buy(P) | 22K | $0.49 | $11K |
| Jan 24, 2024 | Williamson Robert F III | Director | Buy(P) | 30K | $0.49 | $15K |
| Jan 24, 2024 | Puhlmann Markus | Chief Medical Officer | Buy(P) | 280K | $0.50 | $140K |
| Dec 21, 2023 | Williamson Robert F III | Director | Buy(P) | 4K | $0.33 | $1K |
| Dec 19, 2023 | Puhlmann Markus | Chief Medical Officer | Buy(P) | 400K | $0.34 | $136K |
| Dec 19, 2023 | Williamson Robert F III | Director | Buy(P) | 14K | $0.32 | $4K |
| Dec 18, 2023 | Puhlmann Markus | Chief Medical Officer | Buy(P) | 60K | $0.26 | $16K |
| Dec 18, 2023 | Williamson Robert F III | Director | Buy(P) | 10K | $0.26 | $3K |
| Dec 18, 2023 | Hunt Jonathan Robert | Chief Financial Officer | Buy(P) | 125K | $0.26 | $33K |
| Dec 15, 2023 | Woods Lori A | Director | Buy(P) | 153K | $0.27 | $41K |
| Dec 15, 2023 | Puhlmann Markus | Chief Medical Officer | Buy(P) | 135K | $0.27 | $36K |
| Dec 14, 2023 | Woods Lori A | Director | Buy(P) | 32K | $0.27 | $9K |
| Dec 12, 2023 | Woods Lori A | Director | Grant(A) | 230K | — | $0 |
| Dec 12, 2023 | Henson Heidi | Director | Grant(A) | 230K | — | $0 |
| Dec 12, 2023 | Williamson Robert F III | Director | Grant(A) | 230K | — | $0 |
| Dec 12, 2023 | Morich Frank | Director | Grant(A) | 230K | — | $0 |
| Dec 12, 2023 | Hunt Jonathan Robert | Chief Financial Officer | Grant(A) | 1.2M | — | $0 |
| Dec 12, 2023 | Spoor Johan M. | CEO, Director | Grant(A) | 3.3M | — | $0 |
| Dec 12, 2023 | Puhlmann Markus | Chief Medical Officer | Grant(A) | 1.5M | — | $0 |
| Jun 12, 2023 | Austin Mark John | VP Finance/Prin Fin&Acct Offic | Grant(A) | 225K | — | $0 |
| Jun 12, 2023 | Streeter Jennifer | COO & VP of HR | Grant(A) | 500K | — | $0 |
| Jun 2, 2023 | Henson Heidi | Director | Grant(A) | 470K | — | $0 |
| Jun 2, 2023 | Henson Heidi | Director | Grant(A) | 230K | — | $0 |
Insider transactions sourced from SEC EDGAR Form 4 filings, normalized within minutes of acceptance. "Buy"/"Sell" mark open-market transactions (codes P/S), the tradeable signal. Awards, option exercises and tax-withholding are shown with their raw code. All data is public domain.
Coverage: Form 4 filings indexed 2021-03-29 → 2026-07-14. Earlier history is backfilling; this window widens as it deepens.
Programmatic access via the Arkolith API & MCP server (insider.transactions, insider.company).