person · Reporting owner
Kastelein Johannes Jacob Pieter
Disclosed activity across 1 company
Sign in to followReported relationships
Latest disclosed role at each company.
| Company | Last reported as | Report date | Published |
|---|---|---|---|
| NewAmsterdam Pharma Co N.V.NAMS · Entity 1826 | Director · Chief Scientific Officer | September 30, 2026 | October 03, 2026 |
Disclosed balances
About these balances
Latest available filing per company, not a reconstructed current portfolio. Matching sequences show the last reported balance with all source rows expandable; grouping alone does not establish account ownership. Do not add unresolved positions together. Filings may omit unchanged positions, and amendments may correct only part of an older disclosure. Jointly reported shares are not necessarily this owner's personal holdings.
NewAmsterdam Pharma Co N.V.
Report date September 30, 2026 · Filed October 03, 2026
| Security / award | Ownership account | Disclosed shares / units | Disclosure context |
|---|---|---|---|
| Ordinary SharesSEC Table I · non-derivative | IndirectSee footnotes | 69,302 |
Last balance in matching sequence
After 2026-09-30 transaction · row 2
Source-order balances reconcile. Account continuity and personal attribution are not independently verified.
2 source rowsRow 1 · 2026-09-30 · Exercise / conversion · Acquired 50,246 · Balance 119,548 F1: The exercise price of the option is EUR 1.16392. F2: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Row 2 · 2026-09-30 · Sale · Disposed 50,246 · Balance 69,302 F3: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.00 to $25.10 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. |
| Option (right to buy)SEC Table II · derivative / convertible security · Expires 2031-07-06 | IndirectSee footnote | 344,983 |
Reported balance
After 2026-09-30 transaction · row 4
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 4 · 2026-09-30 · Exercise / conversion · Disposed 50,246 · Balance 344,983 F1: The exercise price of the option is EUR 1.16392. F5: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F6: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. |
| Ordinary SharesSEC Table I · non-derivative | Direct | 53,500 |
Reported balance
Holding disclosure · report date 2026-09-30 · row 3
Holding and transaction disclosures are not merged.
1 source rowRow 3 · Balance 53,500 F4: Includes 48,166 ordinary shares subject to restricted stock unit awards that remain subject to vesting. |
Filing footnotes · ownership attribution and instrument terms
F1: The exercise price of the option is EUR 1.16392.
F2: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum.
F3: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.00 to $25.10 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction.
F4: Includes 48,166 ordinary shares subject to restricted stock unit awards that remain subject to vesting.
F5: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date.
F6: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer.
Transaction history
JSON APIPurchases/sales include open-market and private transactions. Plan disclosure applies to the filing; individual rows may differ. “Not disclosed” is not “unplanned.”
The cutoff filters transaction history only. Company summaries and owner relationships show the latest available disclosures. Parser corrections can improve historical records.
| Transaction date | Company | Activity / security | Shares / units | Reported price | Reported value | Details |
|---|---|---|---|---|---|---|
| September 30, 2026 Filed Oct 3, 2026 00:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 50,246 | $0.00 | $0.00 |
DisclosureSEC source: 0001193125-26-412431 · ownership.xml · derivative · entry 4 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 344,983 Underlying: Ordinary Shares · 50,246 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F5 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F6 · ownership.nature: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. Read SEC document |
| September 30, 2026 Filed Oct 3, 2026 00:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 50,246 | $25.03 | $1,257,657.38 |
DisclosureSEC source: 0001193125-26-412431 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnotes Disclosed balance after: 69,302 F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.00 to $25.10 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Read SEC document |
| September 30, 2026 Filed Oct 3, 2026 00:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 50,246 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-412431 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnotes Disclosed balance after: 119,548 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Read SEC document |
| August 24, 2026 Filed Aug 25, 2026 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 125,000 | $0.00 | $0.00 |
DisclosureSEC source: 0001193125-26-365202 · ownership.xml · derivative · entry 4 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 395,229 Underlying: Ordinary Shares · 125,000 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F5 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F6 · ownership.nature: The option was granted to and is held by Futurum through PoolCo for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. Read SEC document |
| August 24, 2026 Filed Aug 25, 2026 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 125,000 | $26.91 | $3,363,750.00 |
DisclosureSEC source: 0001193125-26-365202 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnotes Disclosed balance after: 69,302 F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $26.72 to $27.70 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Read SEC document |
| August 24, 2026 Filed Aug 25, 2026 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 125,000 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-365202 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnotes Disclosed balance after: 194,302 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Read SEC document |
| March 09, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 101,409 | $0.00 | $0.00 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · derivative · entry 9 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 520,229 Underlying: Ordinary Shares · 101,409 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F6 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F7 · ownership.nature: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. Read SEC document |
| March 09, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 101,409 | $30.29 | $3,071,678.61 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 6 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 69,302 F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.00 per share to $30.80 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| March 09, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 101,409 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 5 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 170,711 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| March 06, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 94,124 | $0.00 | $0.00 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · derivative · entry 8 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 621,638 Underlying: Ordinary Shares · 94,124 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F6 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F7 · ownership.nature: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. Read SEC document |
| March 06, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 94,124 | $30.32 | $2,853,839.68 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 4 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 69,302 F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.00 per share to $30.42 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| March 06, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 94,124 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 3 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 163,426 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| March 05, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 104,467 | $0.00 | $0.00 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · derivative · entry 7 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 715,762 Underlying: Ordinary Shares · 104,467 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F6 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F7 · ownership.nature: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer. Read SEC document |
| March 05, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 104,467 | $30.30 | $3,165,350.10 |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 69,302 F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.00 per share to $30.55 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| March 05, 2026 Filed Mar 10, 2026 00:18 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 104,467 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-099073 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Indirect · See footnote Disclosed balance after: 173,769 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| February 20, 2026 Filed Feb 24, 2026 21:40 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 30,789 | $35.46 | $1,091,777.94 |
DisclosureSEC source: 0001193125-26-067260 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 53,500 F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $35.24 to $35.86 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. Read SEC document |
| February 20, 2026 Filed Feb 24, 2026 21:40 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 14,692 | $35.00 | $514,220.00 |
DisclosureSEC source: 0001193125-26-067260 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 84,289 F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.24 to $35.23 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. Read SEC document |
| January 07, 2026 Filed Jan 7, 2026 23:31 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOption (right to buy) · Derivative | 115,000 | $0.00 Strike: $35.45 | $0.00 |
DisclosureSEC source: 0001193125-26-006662 · ownership.xml · derivative · entry 3 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 115,000 Underlying: Ordinary Shares · 115,000 shares Expires 2036-01-07 F5 · derivative.exercise_date: 25% of the shares underlying the option will vest on Janaury 2, 2027, the one-year anniversary of the vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. Read SEC document |
| January 07, 2026 Filed Jan 7, 2026 23:31 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOrdinary Shares | 25,500 | Not disclosed | Not disclosed |
DisclosureSEC source: 0001193125-26-006662 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 98,981 F3 · shares: Represents RSUs, each representing a contingent right to receive one ordinary share. 1/3 of the RSUs will vest on each of the first, second and third anniversaries of the vesting start date, subject to the Reporting Person's continued service through each such date. F4 · price: Each RSU was granted on January 7, 2026 for no consideration. Read SEC document |
| January 05, 2026 Filed Jan 7, 2026 23:31 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 6,000 | $33.25 | $199,500.00 |
DisclosureSEC source: 0001193125-26-006662 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 73,481 F1 · kind: Represents pre-arranged sale of shares by the Reporting Person solely to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units (RSUs) pursuant to sell-to-cover agreement entered into with the Issuer. The sale does not represent a discretionary transaction by the Reporting Person. F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $32.77 to $33.58 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. Read SEC document |
| August 22, 2025 Filed Aug 25, 2025 21:04 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 7,658 | $25.49 | $195,202.42 |
DisclosureSEC source: 0000950170-25-111241 · ownership.xml · nonDerivative · entry 3 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 69,302 F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.39 per share to $25.62 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The ordinary shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the ordinary shares held by Futurum. Read SEC document |
| August 22, 2025 Filed Aug 25, 2025 21:04 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 42,342 | $25.08 | $1,061,937.36 |
DisclosureSEC source: 0000950170-25-111241 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 76,960 F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.39 per share to $25.35 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The ordinary shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the ordinary shares held by Futurum. Read SEC document |
| August 21, 2025 Filed Aug 25, 2025 21:04 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 50,000 | $24.29 | $1,214,500.00 |
DisclosureSEC source: 0000950170-25-111241 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 119,302 F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.73 per share to $24.57 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F2 · ownership.nature: The ordinary shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the ordinary shares held by Futurum. Read SEC document |
| March 26, 2025 Filed Mar 28, 2025 21:20 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionRestricted Stock Unit · Derivative | 45,481 | Not disclosed | Not disclosed |
DisclosureSEC source: 0000950170-25-046947 · ownership.xml · derivative · entry 4 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 0 Underlying: Ordinary Shares · 45,481 shares Expires not disclosed Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F3 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one ordinary share. F5 · price: The RSUs were granted on March 26, 2025 as earnout RSUs pursuant to the BCA. The BCA provided that certain optionholders would receive RSUs of the issuer, determined in accordance with a formula set forth in the BCA and for no additional consideration, if a certain clinical development milestone was achieved within five years of the Closing Date. The Reporting Person's right to receive the earnout RSUs became fixed and irrevocable on the Closing Date. F4 · derivative.exercise_date: Upon grant, all of the RSUs were fully-vested. F4 · derivative.expiration_date: Upon grant, all of the RSUs were fully-vested. Read SEC document |
| March 26, 2025 Filed Mar 28, 2025 21:20 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantRestricted Stock Unit · Derivative | 45,481 | Not disclosed | Not disclosed |
DisclosureSEC source: 0000950170-25-046947 · ownership.xml · derivative · entry 3 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 45,481 Underlying: Ordinary Shares · 45,481 shares Expires not disclosed F3 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one ordinary share. F5 · price: The RSUs were granted on March 26, 2025 as earnout RSUs pursuant to the BCA. The BCA provided that certain optionholders would receive RSUs of the issuer, determined in accordance with a formula set forth in the BCA and for no additional consideration, if a certain clinical development milestone was achieved within five years of the Closing Date. The Reporting Person's right to receive the earnout RSUs became fixed and irrevocable on the Closing Date. F4 · derivative.exercise_date: Upon grant, all of the RSUs were fully-vested. F4 · derivative.expiration_date: Upon grant, all of the RSUs were fully-vested. Read SEC document |
| March 26, 2025 Filed Mar 28, 2025 21:20 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 45,481 | $0.00 | $0.00 |
DisclosureSEC source: 0000950170-25-046947 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 79,481 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| March 26, 2025 Filed Mar 28, 2025 21:20 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOrdinary Shares | 19,302 | $0.00 | $0.00 |
DisclosureSEC source: 0000950170-25-046947 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 169,302 F1 · shares: Reflects ordinary shares issued to Futurum B.V. ("Futurum") for the benefit of the Reporting Person on March 26, 2025 as earnout shares pursuant to the business combination agreement, dated as of July 25, 2022, by and among the issuer, Frazier Lifesicences Acquisition Corporation, NewAmsterdam Pharma Holding B.V., and NewAmsterdam Pharma Investment Corporation (the "BCA"). The BCA provided that certain shareholders would receive additional ordinary shares of the issuer, determined in accordance with a formula set forth in the BCA and for no additional consideration, if a certain clinical development milestone was achieved within five years of November 22, 2022, the date of closing under the BCA (the "Closing Date"). Futurum's right to receive the earnout shares became fixed and irrevocable on the Closing Date. F2 · ownership.nature: The ordinary shares are held by Futurum for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the ordinary shares held by Futurum. Read SEC document |
| March 24, 2025 Filed Mar 26, 2025 20:27 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 150,000 | $0.00 | $0.00 |
DisclosureSEC source: 0000950170-25-045283 · ownership.xml · derivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 820,229 Underlying: Ordinary Shares · 150,000 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is 1.16392 Euros. F3 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F4 · ownership.nature: The option was granted to and is held by Futurum through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the issuer. Read SEC document |
| March 24, 2025 Filed Mar 26, 2025 20:27 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 150,000 | Not disclosed | Not disclosed |
DisclosureSEC source: 0000950170-25-045283 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 150,000 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is 1.16392 Euros. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the Ordinary Shares held by Futurum. Read SEC document |
| January 07, 2025 Filed Jan 7, 2025 22:21 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOrdinary Shares | 34,000 | Not disclosed | Not disclosed |
DisclosureSEC source: 0000950170-25-003018 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 34,000 F1 · shares: Represents restricted stock units (RSUs), each representing a contingent right to receive one ordinary share. 1/3 of the RSUs will vest on each of the first, second and third anniversaries of the vesting start date, subject to the Reporting Person's continued service through each such date. F2 · price: Each RSU was granted on January 7, 2025 for no consideration. Read SEC document |
| January 02, 2025 Filed Jan 6, 2025 22:48 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOption (right to buy) · Derivative | 200,000 | $0.00 Strike: $25.96 | $0.00 |
DisclosureSEC source: 0000950170-25-002356 · ownership.xml · derivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 200,000 Underlying: Ordinary Shares · 200,000 shares Expires 2035-01-02 F1 · derivative.exercise_date: 25% of the shares underlying the option will vest on January 2, 2026, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. Read SEC document |
| March 26, 2024 Filed Mar 27, 2024 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOption (right to buy) · Derivative | 201,673 | $0.00 | $0.00 |
DisclosureSEC source: 0000950170-24-037241 · ownership.xml · derivative · entry 4 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 970,229 Underlying: Ordinary Shares · 201,673 shares Expires 2031-07-06 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_price: The exercise price of the option is EUR 1.16392. F6 · derivative.exercise_date: The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. F7 · ownership.nature: The option was granted to and is held by Futurum through PoolCo for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investement control over the securities held by Futurum through PoolCo. PoolCo has no voting or investement control or pecuniary interest in the securities held on behalf of Futurum. Read SEC document |
| March 26, 2024 Filed Mar 27, 2024 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | SaleOrdinary Shares | 190,476 | $21.50 | $4,095,234.00 |
DisclosureSEC source: 0000950170-24-037241 · ownership.xml · nonDerivative · entry 3 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 0 F4 · shares: These shares were sold in multiple transactions at a price of $21.50 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. F5 · acquired: The Ordinary Shares were sold by the Reporting Person pursuant to an exemption in a lock-up agreement, dated February 12, 2024, in order to satisfy certain tax liabilities. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investement control over the Ordinary Shares held by Futurum through PoolCo. PoolCo has no voting or investement control or pecuniary interest in the Ordinary Shares held on behalf of Futurum. Read SEC document |
| March 26, 2024 Filed Mar 27, 2024 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Tax withholdingOrdinary Shares | 11,197 | $22.72 | $254,395.84 |
DisclosureSEC source: 0000950170-24-037241 · ownership.xml · nonDerivative · entry 2 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 190,476 F3 · shares: Represents Ordinary Shares that were withheld to satisfy the exercise price due upon the exercise of the options. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investement control over the Ordinary Shares held by Futurum through PoolCo. PoolCo has no voting or investement control or pecuniary interest in the Ordinary Shares held on behalf of Futurum. Read SEC document |
| March 26, 2024 Filed Mar 27, 2024 20:30 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | Exercise / conversionOrdinary Shares | 201,673 | Not disclosed | Not disclosed |
DisclosureSEC source: 0000950170-24-037241 · ownership.xml · nonDerivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Indirect · See footnote Disclosed balance after: 201,673 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · price: The exercise price of the option is EUR 1.16392. F2 · ownership.nature: The Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investement control over the Ordinary Shares held by Futurum through PoolCo. PoolCo has no voting or investement control or pecuniary interest in the Ordinary Shares held on behalf of Futurum. Read SEC document |
| January 01, 2024 Filed Jan 3, 2024 22:17 UTC | NewAmsterdam Pharma Co N.V. NAMS · Entity 1826 | GrantOption (right to buy) · Derivative | 500,000 | $0.00 Strike: $11.17 | $0.00 |
DisclosureSEC source: 0000950170-24-001125 · ownership.xml · derivative · entry 1 Kastelein Johannes Jacob Pieter · CIK 0002000389 · Director · Chief Scientific Officer 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 500,000 Underlying: Ordinary Shares · 500,000 shares Expires 2034-01-01 F1 · derivative.exercise_date: 25% of the shares underlying the option will vest on January 1, 2025, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. Read SEC document |
Value uses the disclosed total when available, otherwise shares × reported transaction price. It is not an estimate of exercise cash cost or investment performance.