X0202 SCHEDULE 13D/A 0001076352 XXXXXXXX LIVE 9 Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share 03/13/2026 false 0001804176 124155102 Butterfly Network, Inc.

1600 District Avenue Burlington MA 01803

Jonathan M. Rothberg, Ph.D. (781) 557-4800 c/o Butterfly Network, Inc., 1600 Distri Burlington MA 01803 0001076352 N Rothberg Jonathan M. PF N X1 2821463.00 726696.00 2821463.00 726696.00 3548159.00 N 1.6 IN This Reporting Person's table is for Class A common stock. Rows 7, 9 and 11 consists of (i) 2,799,818 shares of Class A common stock of Butterfly Network, Inc. (f/k/a Longview Acquisition Corp.) (the "Issuer") held by Jonathan M. Rothberg, Ph.D. and (ii) stock options to purchase 21,645 shares of Class A common stock of the Issuer which are exercisable within 60 days of March 13, 2026, held by Dr. Jonathan M. Rothberg. Rows 8, 10 and 11 consists of 726,696 shares of Class A common stock of the Issuer held by Dr. Rothberg's spouse. Row 13 is calculated based on 228,205,930 shares of Class A common stock of the Issuer outstanding as of February 19, 2026. Y Rothberg Jonathan M. PF N X1 26426937.00 0.00 26426937.00 0.00 26426937.00 N 100 IN This Reporting Person's table is for Class B common stock. Rows 7, 9 and 11 consists of 26,426,937 shares of Class B common stock of the Issuer held by 4C Holdings I, LLC, 4C Holdings II, LLC, 4C Holdings III, LLC, 4C Holdings IV, LLC and 4C Holdings V, LLC and shares distributed from 4C Holdings I, LLC and held by entities owned by trusts created for the benefit of Dr. Jonathan Rothberg's children. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Y 4C Holdings I, LLC PF N DE 0.00 4716596.00 0.00 4716596.00 4716596.00 N 17.8 OO This Reporting Person's table is for Class B common stock. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Y 4C Holdings II, LLC PF N DE 0.00 2621701.00 0.00 2621701.00 2621701.00 N 9.9 OO This Reporting Person's table is for Class B common stock. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Y 4C Holdings III, LLC PF N DE 0.00 2621701.00 0.00 2621701.00 2621701.00 N 9.9 OO This Reporting Person's table is for Class B common stock. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Y 4C Holdings IV, LLC PF N DE 0.00 2621701.00 0.00 2621701.00 2621701.00 N 9.9 OO This Reporting Person's table is for Class B common stock. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Y 4C Holdings V, LLC PF N DE 0.00 8845238.00 0.00 8845238.00 8845238.00 N 33.5 OO This Reporting Person's table is for Class B common stock. Row 13 is calculated based on 26,426,937 shares of Class B common stock of the Issuer outstanding as of February 19, 2026. Class A common stock, par value $0.0001 per share, Class B common stock, par value $0.0001 per share Butterfly Network, Inc. 1600 District Avenue Burlington MA 01803 Explanatory Note This Amendment No. 9 to Schedule 13D ("Amendment No. 9") amends and supplements the Schedule 13D filed on February 22, 2021, as amended by Amendment No. 1 filed on March 26, 2021, Amendment No. 2 filed on March 28, 2022, Amendment No. 3 filed on September 16, 2022, Amendment No. 4 filed on September 13, 2023, Amendment No. 5 filed on August 30, 2024, Amendment No. 6 filed on March 7, 2025, Amendment No. 7 filed on December 1, 2025 and Amendment No. 8 filed on December 17, 2025 (as amended, the "Schedule 13D") relating to the Class A common stock, par value $0.0001 per share, and Class B common stock, par value $0.0001 per share, of Butterfly Network, Inc. (f/k/a Longview Acquisition Corp.), a Delaware corporation (the "Issuer"). Information reported in the Schedule 13D remains in effect except to the extent that it is amended, restated or superseded by information contained in this Amendment No. 9. Capitalized terms used but not defined herein have the meanings ascribed to them in the Schedule 13D. Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following: In connection with estate planning, Dr. Rothberg and entities owned by trusts created for the benefit of Dr. Rothberg's children have entered into a trading plan pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (the "Plan"), a copy of which is attached hereto as Exhibit 6. Pursuant to the Plan, sales of up to 2,799,818 shares of Class A common stock and 5,000,000 shares of Class B common stock may be effected during the plan sales period beginning following the cooling-off period contained in Rule 10b5-1(c) on July 14, 2026 and ending on July 14, 2027 in accordance with the terms and conditions of the Plan. The sale of shares of Class A common stock and Class B common stock under the Plan is subject to minimum price and volume parameters included in the Plan, and there is no assurance that any shares of Class A common stock or Class B common stock will be sold under the Plan. Item 7 of the Schedule 13D is hereby amended by adding the following exhibit: Exhibit No. 6 - Rule 10b5-1 Trading Plan Rothberg Jonathan M. /s/ Jonathan M. Rothberg 03/17/2026 Rothberg Jonathan M. /s/ Jonathan M. Rothberg 03/17/2026 4C Holdings I, LLC /s/ Jonathan M. Rothberg 03/17/2026 4C Holdings II, LLC /s/ Jonathan M. Rothberg 03/17/2026 4C Holdings III, LLC /s/ Jonathan M. Rothberg 03/17/2026 4C Holdings IV, LLC /s/ Jonathan M. Rothberg 03/17/2026 4C Holdings V, LLC /s/ Jonathan M. Rothberg 03/17/2026