Perceptive Advisors group reports 9.1% Nautilus (NAUT) ownership in updated 13D/A

Rhea-AI Filing Summary

Nautilus Biotechnology, Inc. received an updated ownership report from Perceptive Advisors and related entities. The group reports beneficial ownership of 11,634,211 shares of Nautilus common stock, representing 9.1% of the class, based on 127,255,223 shares outstanding as of July 24, 2026.

Perceptive Life Sciences Master Fund, Ltd. directly holds 11,468,351 shares, and C2 Life Sciences LLC directly holds 165,860 shares. Perceptive Advisors LLC, as investment manager to both entities, and its managing member Joseph Edelman share voting and dispositive power over these holdings, while neither Perceptive Advisors nor Edelman holds Nautilus shares directly.

Key Figures

Beneficial ownership: 11,634,211 shares Ownership percentage: 9.1% Shares outstanding: 127,255,223 shares +2 more

5 metrics

Beneficial ownership 11,634,211 shares Total Nautilus common shares beneficially owned by Perceptive reporting group

Ownership percentage 9.1% Percent of Nautilus common stock represented by 11,634,211 shares

Shares outstanding 127,255,223 shares Nautilus common shares outstanding as of July 24, 2026

Master Fund holdings 11,468,351 shares Nautilus shares directly held by Perceptive Life Sciences Master Fund, Ltd.

C2 holdings 165,860 shares Nautilus shares directly held by C2 Life Sciences LLC

Key Terms

beneficially owned, shared voting power, shared dispositive power, investment manager, +1 more

5 terms

beneficially owned financial

"The information set forth in rows 11 and 13... Aggregate amount beneficially owned"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

shared voting power financial

"Number of Shares Beneficially Owned... Shared Voting Power 11,634,211.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"Number of Shares Beneficially Owned... Shared Dispositive Power 11,634,211.00"

investment manager financial

"Perceptive Advisors serves as the investment manager to the Master Fund and C2."

Schedule 13D regulatory

"If the filing person has previously filed a statement on Schedule 13G..."

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

FAQ

How much of Nautilus Biotechnology (NAUT) does Perceptive Advisors currently beneficially own?

Perceptive Advisors and related entities report beneficial ownership of 11,634,211 Nautilus shares, representing 9.1% of the company’s common stock. This percentage is calculated using 127,255,223 shares outstanding as of July 24, 2026, as disclosed in Nautilus’s Form 10-Q.

Which Perceptive entities hold Nautilus Biotechnology (NAUT) shares and in what amounts?

Perceptive Life Sciences Master Fund, Ltd. directly holds 11,468,351 Nautilus shares, while C2 Life Sciences LLC directly holds 165,860 shares. Together these positions total 11,634,211 shares of Nautilus common stock reported as beneficially owned by the Perceptive group.

What percentage of Nautilus Biotechnology (NAUT) does Perceptive Advisors’ group own?

The reporting group led by Perceptive Advisors reports owning 9.1% of Nautilus’s common stock. This ownership percentage is based on 127,255,223 shares outstanding as of July 24, 2026, according to Nautilus’s most recent quarterly report referenced in the filing.

Does Perceptive Advisors LLC or Joseph Edelman directly hold Nautilus (NAUT) shares?

Neither Perceptive Advisors LLC nor Joseph Edelman directly holds Nautilus common stock. The filing states that the shares are directly held by Perceptive Life Sciences Master Fund, Ltd. and C2 Life Sciences LLC, with Perceptive Advisors and Edelman exercising shared voting and dispositive power.

What role does Perceptive Advisors play in managing Nautilus (NAUT) holdings?

Perceptive Advisors LLC serves as the investment manager to both Perceptive Life Sciences Master Fund, Ltd. and C2 Life Sciences LLC. Through this role, Perceptive Advisors, and its managing member Joseph Edelman, have shared voting and dispositive power over the Nautilus shares held by those entities.

On what date is the Nautilus (NAUT) ownership information in this Schedule 13D/A based?

The ownership percentages are calculated using Nautilus’s reported 127,255,223 shares outstanding as of July 24, 2026. This share count comes from Nautilus’s Form 10-Q filed on July 28, 2026, which the reporting group cites as the basis for its 9.1% ownership figure.

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Available on EDGAR 08/14/2026 - 05:21 PM Accepted by SEC EDGAR 08/14/2026 - 05:20 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 5)

Nautilus Biotechnology, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

63909J108

(CUSIP Number)

Perceptive Advisors LLC
Alexander Rakitin, 51 Astor Place, 10th Floor
New York, NY, 10003
646-205-5345

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

06/30/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Perceptive Advisors LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,634,211.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,634,211.00

11

Aggregate amount beneficially owned by each reporting person

11,634,211.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.1 %

14

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Joseph Edelman

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,634,211.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,634,211.00

11

Aggregate amount beneficially owned by each reporting person

11,634,211.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.1 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Perceptive Life Sciences Master Fund, Ltd.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,468,351.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,468,351.00

11

Aggregate amount beneficially owned by each reporting person

11,468,351.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.1 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

C2 Life Sciences LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 165,860.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 165,860.00

11

Aggregate amount beneficially owned by each reporting person

165,860.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.1 %

14

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.0001 per share
(b)	Name of Issuer: Nautilus Biotechnology, Inc.
(c)	Address of Issuer's Principal Executive Offices: 2701 Eastlake Avenue East, Seattle, WASHINGTON , 98102.
Item 5.	Interest in Securities of the Issuer
(a)	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 percentages set forth in row 13 are based on 127,255,223 shares of Common Stock outstanding as of July 24, 2026, as disclosed by the Issuer in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on July 28, 2026.
(b)	The information set forth in rows 7 through 10 of the cover pages to this Schedule 13D is incorporated by reference. Neither Perceptive Advisors LLC ( "Perceptive Advisors") nor Joseph Edelman ("Mr. Edelman") directly holds any Common Stock. Perceptive Life Sciences Master Fund, Ltd. (the "Master Fund") directly holds 11,468,351 shares of Common Stock, and C2 Life Sciences LLC ("C2") directly holds 165,860 shares of Common Stock. Perceptive Advisors serves as the investment manager to the Master Fund and C2. Mr. Edelman is the managing member of Perceptive Advisors.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Perceptive Advisors LLC

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman, Managing Member
Date:	08/14/2026

Joseph Edelman

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman
Date:	08/14/2026

Perceptive Life Sciences Master Fund, Ltd.

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman, Managing Member
Date:	08/14/2026

C2 Life Sciences LLC

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman, Managing Member
Date:	08/14/2026