SCHEDULE 13D/A 0001193125-21-195221 0001224962 XXXXXXXX LIVE 4 Common Stock, $0.0001 par value per share 06/20/2025 false 0001808805 63909J108 Nautilus Biotechnology, Inc.

2701 Eastlake Avenue East Seattle WA 98102

Alexander Rakitin (646) 205-5340 Perceptive Advisors LLC 51 Astor Place, 10th Floor New York NY 10003 Louis Rambo (202) 416-6800 Proskauer Rose LLP 1001 Pennsylvania Ave, Ste 600 Washington DC 20004 0001224962 N Perceptive Advisors LLC b AF Y DE 0.00 12815113.00 0.00 12815113.00 12815113.00 N 10.1 IA 0001164426 N Joseph Edelman b AF Y X1 0.00 12815113.00 0.00 12815113.00 12815113.00 N 10.1 IN 0001249675 N Perceptive Life Sciences Master Fund, Ltd. b WC Y E9 0.00 12649253.00 0.00 12649253.00 12649253.00 N 10.0 CO Common Stock, $0.0001 par value per share Nautilus Biotechnology, Inc. 2701 Eastlake Avenue East Seattle WA 98102 Item 4 of the Schedule 13D is hereby amended and supplemented as follows: On June 20, 2025, Michael Altman, a Managing Director of Perceptive Advisors who has served on the Issuer's board of directors (the "Board") since June 2021, ceased serving as a member of the Board following the expiration of his term. Mr. Altman did not stand for re-election at the Issuer's 2025 Annual Meeting of Stockholders. Item 5(a) of the Schedule 13D is hereby amended and restated as follows: The information set forth in rows 11 and 13 of the cover pages to this Schedule 13D is incorporated by reference. The amounts reported to be beneficially owned by the Reporting Persons include an aggregate of 220,902 shares of Common Stock underlying stock options granted to Mr. Altman (the "Options"). The Master Fund has the right to receive the director compensation provided in respect of Mr. Altman's board service through a partial management fee offset. The percentages set forth in row 13 are based on 126,148,469 outstanding shares of Common Stock as of April 22, 2025, as reported by the Issuer in its Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on April 29, 2025, and assume the exercise of the Options for an aggregate of 220,902 shares of Common Stock. The information set forth in rows 7 through 10 of the cover pages to this Schedule 13D is incorporated by reference. Perceptive Advisors LLC /s/ Joseph Edelman 06/24/2025 Joseph Edelman /s/ Joseph Edelman 06/24/2025 Perceptive Life Sciences Master Fund, Ltd. /s/ Joseph Edelman 06/24/2025