{"transactions":[{"id":1036087,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":52650,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F6","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":52650},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":10,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036086,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":52650,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F6","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":52650},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":9,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036085,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":18000,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F6","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":18000},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036084,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":18000,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F6","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":18000},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036083,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":18000,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F6","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F7","text":"At the Effective Time, pursuant to the Merger Agreement, each PRSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the maximum number of Shares issuable in settlement of such PRSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":18000},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036082,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":210700,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."}],"balance_after":0,"derivative":{"exercise_price":6.16,"expiration_date":"2035-01-17","underlying":"Common Stock","underlying_shares":210700},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036081,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":214200,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."}],"balance_after":0,"derivative":{"exercise_price":14.36,"expiration_date":"2034-02-12","underlying":"Common Stock","underlying_shares":214200},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036080,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":615240,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"At the Effective Time, pursuant to the Merger Agreement, each stock option (\"Option\") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no consideration."}],"balance_after":0,"derivative":{"exercise_price":5.75,"expiration_date":"2033-11-06","underlying":"Common Stock","underlying_shares":615240},"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036079,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Common Stock","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":129101,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"shares","element":"transactionShares","label":"F3","text":"Represents restricted stock units (\"RSUs\") granted to the Reporting Person pursuant to the Issuer's 2018 Equity Incentive Plan. Each RSU represents a contingent right to receive one share of Common Stock on the vesting dates of the RSU."},{"field":"price","element":"transactionPricePerShare","label":"F4","text":"At the Effective Time, pursuant to the Merger Agreement, each RSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the total number of Shares issuable in settlement of such RSU award immediately prior to the Effective Time, multiplied by (b) the Merger Consideration."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1036078,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Common Stock","published_at":"2025-09-18T21:08:14.000Z","date":"2025-09-16","kind":"other","planned":false,"acquired":false,"shares":7982,"price":8.6,"value":68645.2,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"Pursuant to the Agreement and Plan of Merger (the \"Merger Agreement\"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the \"Issuer\"), Yosemite Merger Sub, Inc. (\"Purchaser\"), Perseus BidCo US, Inc., a Delaware corporation (\"Parent\"), and Stark International Lux, a Luxembourg private limited liability company (\"Ultimate Parent\"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a \"Share\") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the \"Merger\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Pursuant to the terms of the Merger Agreement, the Shares were tendered at the Offer Acceptance Time (as defined in the Merger Agreement) in exchange for the right to receive $8.60 per Share, in cash, without interest, subject to any applicable withholding of taxes (the \"Merger Consideration\"). At the effective time of the Merger (being such date and at such time as the certificate of merger in respect of the Merger was duly filed with the Secretary of State of the State of Delaware in accordance with the DGCL) (the \"Effective Time\"), each issued and outstanding Share was cancelled in exchange for the Merger Consideration."}],"balance_after":0,"source":{"system":"sec-edgar","filing":"0001948795-25-000004","document":"form4-09192025_010910.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000194879525000004/form4-09192025_010910.xml","form_type":"4"}},{"id":1211425,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Common Stock","published_at":"2025-03-11T20:17:08.000Z","date":"2025-03-07","kind":"sale","planned":false,"acquired":false,"shares":3917,"price":5.2,"value":20368.4,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Nondiscretionary sale to cover tax liability associated with the vesting and settlement of restricted stock units."}],"balance_after":137083,"source":{"system":"sec-edgar","filing":"0001415889-25-007738","document":"form4-03122025_120304.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588925007738/form4-03122025_120304.xml","form_type":"4"}},{"id":1297196,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2025-01-22T19:00:02.000Z","date":"2025-01-17","kind":"grant","planned":false,"acquired":true,"shares":210700,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F2","text":"Represents stock options granted to the Reporting Person pursuant to the Issuer's 2018 Equity Incentive Plan."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The stock options shall vest and become exercisable as to 25% of the shares subject to the option on January 17, 2026, and thereafter vest and become exercisable as to 1/48th of the shares in equal monthly installments, until such time as the option is 100% vested, subject to the Reporting Person's continued service to the Issuer on each vesting date."}],"balance_after":210700,"derivative":{"exercise_price":6.16,"expiration_date":"2035-01-17","underlying":"Common Stock","underlying_shares":210700},"source":{"system":"sec-edgar","filing":"0001415889-25-001875","document":"form4-01222025_110159.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588925001875/form4-01222025_110159.xml","form_type":"4"}},{"id":1297195,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Common Stock","published_at":"2025-01-22T19:00:02.000Z","date":"2025-01-17","kind":"grant","planned":false,"acquired":true,"shares":105300,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units (\"RSUs\") granted to the Reporting Person pursuant to the Issuer's 2018 Equity Incentive Plan. Each RSU represents a contingent right to receive one share of Common Stock on the vesting dates of the RSU. The RSUs vest by 1/3 on each of January 17, 2026, January 17, 2027 and January 17, 2028, subject to the Reporting Person's continued service to the Issuer on each vesting date."}],"balance_after":141000,"source":{"system":"sec-edgar","filing":"0001415889-25-001875","document":"form4-01222025_110159.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588925001875/form4-01222025_110159.xml","form_type":"4"}},{"id":1642569,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Restricted Stock Units","published_at":"2024-02-14T16:30:25.000Z","date":"2024-02-12","kind":"grant","planned":false,"acquired":true,"shares":54000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F4","text":"Performance-Based RSUs (\"PRSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each PRSU represents a contingent right to receive one share of Common Stock on the vesting dates of the PRSU."},{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F5","text":"1/3 of the PRSUs vest on each of February 12, 2025, February 12, 2026 and February 12, 2027, in each case, if the average closing price per share of the Issuer's common stock over the preceding 30 trading day period is greater or equal to $10.00 per share, subject to the continuing employment of the Reporting Person through each vesting date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"1/3 of the PRSUs vest on each of February 12, 2025, February 12, 2026 and February 12, 2027, in each case, if the average closing price per share of the Issuer's common stock over the preceding 30 trading day period is greater or equal to $10.00 per share, subject to the continuing employment of the Reporting Person through each vesting date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F5","text":"1/3 of the PRSUs vest on each of February 12, 2025, February 12, 2026 and February 12, 2027, in each case, if the average closing price per share of the Issuer's common stock over the preceding 30 trading day period is greater or equal to $10.00 per share, subject to the continuing employment of the Reporting Person through each vesting date."}],"balance_after":54000,"derivative":{"underlying":"Common Stock","underlying_shares":54000},"source":{"system":"sec-edgar","filing":"0001415889-24-003743","document":"form4-02142024_040201.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588924003743/form4-02142024_040201.xml","form_type":"4"}},{"id":1642568,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2024-02-14T16:30:25.000Z","date":"2024-02-12","kind":"grant","planned":false,"acquired":true,"shares":214200,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F2","text":"Stock options granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The stock options shall vest and become exercisable as to 25% of the shares subject to the option on February 12, 2025, and thereafter vest and become exercisable as to 1/48th of the shares in equal monthly installments, until such time as the option is 100% vested, subject to the continuing employment of the Reporting Person through each vesting date."}],"balance_after":214200,"derivative":{"exercise_price":14.36,"expiration_date":"2034-02-12","underlying":"Common Stock","underlying_shares":214200},"source":{"system":"sec-edgar","filing":"0001415889-24-003743","document":"form4-02142024_040201.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588924003743/form4-02142024_040201.xml","form_type":"4"}},{"id":1642567,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"PRESIDENT & CEO"}}],"security":"Common Stock","published_at":"2024-02-14T16:30:25.000Z","date":"2024-02-12","kind":"grant","planned":false,"acquired":true,"shares":35700,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents 35,750 restricted stock units (\"RSUs\") granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc. Each RSU represents a contingent right to receive one share of Common Stock on the vesting dates of the RSU. The RSUs vest by 1/3 on each of February 12, 2025, February 12, 2026 and February 12, 2027 subject to the continuing employment of the Reporting Person through each vesting date."}],"balance_after":35700,"source":{"system":"sec-edgar","filing":"0001415889-24-003743","document":"form4-02142024_040201.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000141588924003743/form4-02142024_040201.xml","form_type":"4"}},{"id":1746468,"issuer":{"id":75095,"kind":"organization","name":"Y-mAbs Therapeutics, Inc.","symbol":"YMAB"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"President and CEO"}}],"security":"Employee Stock Option (right to buy)","published_at":"2023-11-08T17:16:53.000Z","date":"2023-11-06","kind":"grant","planned":false,"acquired":true,"shares":615240,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F1","text":"Stock options granted to the Reporting Person pursuant to the 2018 Equity Incentive Plan of Y-mAbs Therapeutics, Inc."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The stock options shall vest and become exercisable as to 25% of the shares subject to the option on November 6, 2024, and thereafter vest and become exercisable as to 1/48th of the shares in equal monthly installments, until such time as the option is 100% vested, subject to the continuing employment of the Reporting Person on each vesting date."}],"balance_after":615240,"derivative":{"exercise_price":5.75,"expiration_date":"2033-11-06","underlying":"Common Stock","underlying_shares":615240},"source":{"system":"sec-edgar","filing":"0001104659-23-115815","document":"tm2330155-2_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1722964/000110465923115815/tm2330155-2_4seq1.xml","form_type":"4"}},{"id":1750747,"issuer":{"id":394,"kind":"organization","name":"Mirion Technologies, Inc.","symbol":"MIR"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Medical Group President"}}],"security":"Class A Common Stock","published_at":"2023-11-03T20:23:43.000Z","date":"2023-11-01","kind":"tax_withholding","planned":false,"acquired":false,"shares":5514,"price":6.93,"value":38212.02,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents shares that have been withheld by the Issuer in satisfaction of tax withholding obligations in connection of the vesting of restricted stock units (RSUs) previously granted to the Reporting Person.  Such withholding was mandated by a policy adopted in advance and does not represent a discretionary trade by the Reporting Person."}],"balance_after":116173,"source":{"system":"sec-edgar","filing":"0001628280-23-036736","document":"wk-form4_1699043012.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1809987/000162828023036736/wk-form4_1699043012.xml","form_type":"4"}},{"id":1934547,"issuer":{"id":394,"kind":"organization","name":"Mirion Technologies, Inc.","symbol":"MIR"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Medical Group President"}}],"security":"Class A Common Stock","published_at":"2023-03-31T20:32:25.000Z","date":"2023-03-29","kind":"grant","planned":false,"acquired":true,"shares":41242,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units that will vest in three equal annual installments starting on April 1, 2024, subject to the Reporting Person's continued employment through each vesting date."}],"balance_after":121687,"source":{"system":"sec-edgar","filing":"0001628280-23-010186","document":"wf-form4_168029473296283.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1809987/000162828023010186/wf-form4_168029473296283.xml","form_type":"4"}},{"id":2126548,"issuer":{"id":394,"kind":"organization","name":"Mirion Technologies, Inc.","symbol":"MIR"},"owners":[{"id":75190,"kind":"person","name":"Rossi Michael J","position":1,"cik":"0001948795","reported_name":"Rossi Michael J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Medical Group President"}}],"security":"Common Stock","published_at":"2022-11-03T20:48:19.000Z","date":"2022-11-01","kind":"grant","acquired":true,"shares":80445,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Represents restricted stock units that will vest in four equal annual installments subject to the Reporting Person's continued employment through each vesting date."}],"balance_after":80445,"source":{"system":"sec-edgar","filing":"0001628280-22-028251","document":"wf-form4_166750848335110.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1809987/000162828022028251/wf-form4_166750848335110.xml","form_type":"4"}}]}