William K Heiden
Insider
First SEC filing: June 11, 2026 · Latest: June 11, 2026
Insider at
Insider transactions
0 buys (P)
0 sells (S)
Net: $0
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| June 9, 2026 | ATRA | A | 12,000 | · | · | 34,188 Direct | +54.08% | Acquired | (price as of 2026-10-02) |
| May 19, 2026 | MGNX | A | 22,000 | · | · | 22,000 Direct | · | Acquired | (price as of 2026-10-02) |
| May 19, 2026 | MGNX | A | 3,750 | · | · | 3,750 Direct | · | Acquired | (price as of 2026-10-02) |
| May 18, 2026 | MGNX | M | 3,750 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| May 18, 2026 | MGNX | M | 3,750 | · | · | 114,750 Direct | +3.38% | Acquired | (price as of 2026-10-02) |
| Aug. 20, 2025 | MGNX | P | 49,500 | $1.49 | $73,755 | 111,000 Direct | +80.49% | Acquired | 140.3% (price as of 2026-10-02) |
| Aug. 19, 2025 | MGNX | P | 50,500 | $1.52 | $76,760 | 61,500 Direct | +459.09% | Acquired | 135.5% (price as of 2026-10-02) |
| June 10, 2025 | ATRA | A | 7,828 | · | · | 22,188 Direct | +54.51% | Acquired | (price as of 2026-10-02) |
| May 21, 2025 | MGNX | A | 22,000 | · | · | 22,000 Direct | · | Acquired | (price as of 2026-10-02) |
| May 21, 2025 | MGNX | A | 3,750 | · | · | 3,750 Direct | · | Acquired | (price as of 2026-10-02) |
| May 20, 2025 | MGNX | M | 6,500 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| May 20, 2025 | MGNX | M | 6,500 | · | · | 11,000 Direct | +144.44% | Acquired | (price as of 2026-10-02) |
| May 21, 2024 | MGNX | A | 16,500 | · | · | 16,500 Direct | · | Acquired | (price as of 2026-10-02) |
| May 21, 2024 | MGNX | A | 6,500 | · | · | 6,500 Direct | · | Acquired | (price as of 2026-10-02) |
| May 20, 2024 | MGNX | M | 4,500 | · | · | 0 Direct | -100.00% | Disposed | (price as of 2026-10-02) |
| May 20, 2024 | MGNX | M | 4,500 | · | · | 4,500 Direct | · | Acquired | (price as of 2026-10-02) |
| March 31, 2024 | ATRA | A | 150,000 | · | · | 359,000 Direct | +71.77% | Acquired | (price as of 2026-10-02) |
| Nov. 10, 2023 | ATRA | P | 100,000 | $0.25 | $25,000 | 209,000 Direct | +91.74% | Acquired | 51.7% (price as of 2026-10-02) |
| May 31, 2023 | MGNX | A | 4,500 | · | · | 4,500 Direct | · | Acquired | (price as of 2026-10-02) |
| May 31, 2023 | MGNX | A | 19,000 | · | · | 19,000 Direct | · | Acquired | (price as of 2026-10-02) |
| May 31, 2023 | ATRA | A | 79,500 | · | · | 79,500 Direct | · | Acquired | (price as of 2026-10-02) |
| May 31, 2023 | ATRA | A | 57,000 | · | · | 109,000 Direct | +109.62% | Acquired | (price as of 2026-10-02) |
| June 23, 2022 | ATRA | A | 31,500 | · | · | 31,500 Direct | · | Acquired | (price as of 2026-10-02) |
| June 23, 2022 | ATRA | A | 20,500 | · | · | 52,000 Direct | +65.08% | Acquired | (price as of 2026-10-02) |
| May 23, 2022 | MGNX | A | 36,000 | · | · | 36,000 Direct | · | Acquired | (price as of 2026-10-02) |
| June 8, 2021 | ATRA | A | 11,000 | · | · | 31,500 Direct | +53.66% | Acquired | (price as of 2026-10-02) |
| June 8, 2021 | ATRA | A | 17,500 | · | · | 17,500 Direct | · | Acquired | (price as of 2026-10-02) |
| June 16, 2020 | ATRA | A | 24,500 | · | · | 24,500 Direct | · | Acquired | (price as of 2026-10-02) |
| June 16, 2020 | ATRA | A | 8,000 | · | · | 20,500 Direct | +64.00% | Acquired | (price as of 2026-10-02) |
| June 27, 2019 | ATRA | A | 13,000 | · | · | 13,000 Direct | · | Acquired | (price as of 2026-10-02) |
| June 27, 2019 | ATRA | A | 4,000 | · | · | 12,500 Direct | +47.06% | Acquired | (price as of 2026-10-02) |
| June 14, 2018 | ATRA | A | 5,000 | · | · | 5,000 Direct | · | Acquired | (price as of 2026-10-02) |
| June 14, 2018 | ATRA | A | 1,500 | · | · | 8,500 Direct | +21.43% | Acquired | (price as of 2026-10-02) |
| June 8, 2017 | ATRA | A | 5,000 | · | · | 7,000 Direct | +250.00% | Acquired | (price as of 2026-10-02) |
| June 8, 2017 | ATRA | A | 21,500 | · | · | 21,500 Direct | · | Acquired | (price as of 2026-10-02) |
| Jan. 3, 2017 | ATRA | A | 5,500 | · | · | 5,500 Direct | · | Acquired | (price as of 2026-10-02) |
| Jan. 3, 2017 | ATRA | A | 2,000 | · | · | 2,000 Direct | · | Acquired | (price as of 2026-10-02) |
| Jan. 4, 2016 | ATRA | A | 10,500 | · | · | 10,500 Direct | · | Acquired | (price as of 2026-10-02) |
| Nov. 23, 2015 | ATRA | A | 15,500 | · | · | 15,500 Direct | · | Acquired | (price as of 2026-10-02) |
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II) Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| May 19, 2026 | MGNX | Stock Option (right to buy) | Common Stock | $4.52 | May 19, 2036 | 22,000 | Acquired |
| May 19, 2026 | MGNX | Restricted Stock Unit | Common Stock | · | · | 3,750 | Acquired |
| May 18, 2026 | MGNX | Restricted Stock Unit | Common Stock | · | · | 3,750 | Disposed |
| May 21, 2025 | MGNX | Stock Option (right to buy) | Common Stock | $1.49 | May 21, 2035 | 22,000 | Acquired |
| May 21, 2025 | MGNX | Restricted Stock Unit | Common Stock | · | · | 3,750 | Acquired |
| May 20, 2025 | MGNX | Restricted Stock Unit | Common Stock | · | · | 6,500 | Disposed |
| May 21, 2024 | MGNX | Stock Option (right to buy) | Common Stock | $4.26 | May 21, 2034 | 16,500 | Acquired |
| May 21, 2024 | MGNX | Restricted Stock Unit | Common Stock | · | · | 6,500 | Acquired |
| May 20, 2024 | MGNX | Restricted Stock Unit | Common Stock | · | · | 4,500 | Disposed |
| May 31, 2023 | MGNX | Restricted Stock Unit | Common Stock | · | · | 4,500 | Acquired |
| May 31, 2023 | MGNX | Stock Option (right to buy) | Common Stock | $4.67 | May 31, 2033 | 19,000 | Acquired |
| May 31, 2023 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $1.53 | May 30, 2033 | 79,500 | Acquired |
| June 23, 2022 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $7.35 | June 22, 2032 | 31,500 | Acquired |
| May 23, 2022 | MGNX | Stock Option (right to buy) | Common Stock | $3.96 | May 23, 2032 | 36,000 | Acquired |
| June 8, 2021 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $13.80 | June 7, 2031 | 17,500 | Acquired |
| June 16, 2020 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $10.54 | June 15, 2030 | 24,500 | Acquired |
| June 27, 2019 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $20.25 | June 26, 2029 | 13,000 | Acquired |
| June 14, 2018 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $45.65 | June 13, 2025 | 5,000 | Acquired |
| June 8, 2017 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $13.20 | June 8, 2024 | 21,500 | Acquired |
| Jan. 3, 2017 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $15.08 | Jan. 3, 2024 | 5,500 | Acquired |
| Jan. 4, 2016 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $24.05 | Jan. 4, 2023 | 10,500 | Acquired |
| Nov. 23, 2015 | ATRA | Non-Qualified Stock Option (Right to Buy) | Common Stock | $34.98 | Nov. 22, 2022 | 15,500 | Acquired |
Exercise/conversion price is blank when not applicable (e.g. RSUs).