Andreessen Horowitz sells Nautilus (NAUT) shares around $1

Rhea-AI Filing Summary

Nautilus Biotechnology, Inc. (NAUT) received an Amendment No. 3 to a Schedule 13D from venture funds affiliated with Andreessen Horowitz reporting updated ownership and recent trading activity in Nautilus common stock.

The filing states that AH Bio Fund II, L.P. beneficially owns 7,094,691 shares of Nautilus common stock, representing 5.6% of the class, and Andreessen Horowitz LSV Fund II, L.P. beneficially owns 590,241 shares, representing 0.5%. Marc L. Andreessen and Benjamin A. Horowitz are reported as having shared voting and dispositive power over an aggregate 7,684,932 shares, or 6.0% of Nautilus’ common stock.

The reported ownership percentages are based on 127,255,223 shares outstanding as of July 24, 2026. The funds disclose multiple open market sales of Nautilus shares between July 31 and August 27, 2026, at weighted average prices generally around $0.90–$1.05 per share, and undertake to provide full pricing breakdowns upon request.

Key Figures

Beneficial ownership – AH Bio Fund II, L.P.: 7,094,691 shares (5.6%) Beneficial ownership – Andreessen Horowitz LSV Fund II, L.P.: 590,241 shares (0.5%) Aggregate beneficial ownership – Marc L. Andreessen: 7,684,932 shares (6.0%) +3 more

6 metrics

Beneficial ownership – AH Bio Fund II, L.P. 7,094,691 shares (5.6%) Common stock of Nautilus Biotechnology based on 127,255,223 shares outstanding as of July 24, 2026

Beneficial ownership – Andreessen Horowitz LSV Fund II, L.P. 590,241 shares (0.5%) Common stock of Nautilus Biotechnology based on 127,255,223 shares outstanding as of July 24, 2026

Aggregate beneficial ownership – Marc L. Andreessen 7,684,932 shares (6.0%) Shares over which he has shared voting and dispositive power

Aggregate beneficial ownership – Benjamin A. Horowitz 7,684,932 shares (6.0%) Shares over which he has shared voting and dispositive power

Shares outstanding – Nautilus Biotechnology common stock 127,255,223 shares Outstanding as of July 24, 2026, per Form 10-Q

Example sale – AH Bio II on August 26, 2026 231,738 shares at $0.93 weighted average price Open market sale with price range $0.93–$0.95 per share

Key Terms

beneficially owned, sole voting power, sole dispositive power, open market sale, +1 more

5 terms

beneficially owned financial

"set forth the aggregate number of shares of common stock ... 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.

sole voting power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: | 7 | Sole Voting Power"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

sole dispositive power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: | 9 | Sole Dispositive Power"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

open market sale financial

"Open Market Sale AH Bio II 07/31/2026 85,157 0.98 0.95 1.05"

An open market sale is when a company or a shareholder sells shares through the regular stock market to any willing buyer, using ordinary exchange trading rather than private deals. It matters to investors because it increases the number of shares available and can push the price down or change ownership balance—think of it like someone putting extra items on a supermarket shelf for any shopper to buy, which can lower the item's price if supply suddenly grows.

Schedule 13D regulatory

"This Amendment No. 3 ... amends and supplements the statement on originally filed"

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

What percentage of Nautilus Biotechnology (NAUT) does AH Bio Fund II, L.P. report owning?

AH Bio Fund II, L.P. reports beneficial ownership of 7,094,691 shares of Nautilus Biotechnology common stock, representing 5.6% of the outstanding common stock, based on 127,255,223 shares outstanding as of July 24, 2026.

How many Nautilus (NAUT) shares does Andreessen Horowitz LSV Fund II, L.P. beneficially own?

Andreessen Horowitz LSV Fund II, L.P. reports beneficial ownership of 590,241 shares of Nautilus Biotechnology common stock, representing 0.5% of the class, using 127,255,223 shares outstanding as the reference share count.

What is the total Nautilus (NAUT) stake attributed to Marc Andreessen and Ben Horowitz in this filing?

Marc L. Andreessen and Benjamin A. Horowitz each report shared voting and dispositive power over 7,684,932 shares of Nautilus Biotechnology common stock, representing 6.0% of the company’s outstanding common stock.

What share count for Nautilus (NAUT) outstanding stock is used to calculate the reported ownership percentages?

The reported ownership percentages are calculated using 127,255,223 shares of Nautilus Biotechnology common stock outstanding as of July 24, 2026, as disclosed in Nautilus’ Form 10-Q filed on July 28, 2026.

What recent trading activity in Nautilus (NAUT) shares do the Andreessen Horowitz funds disclose?

The funds disclose multiple open market sales of Nautilus shares between July 31 and August 27, 2026, with weighted average prices generally around $0.90 to $1.05 per share, and they undertake to provide full per-trade price information upon request.

Who are the reporting persons in the Nautilus (NAUT) Schedule 13D/A Amendment No. 3?

The reporting persons are AH Bio Fund II, L.P., AH Equity Partners Bio II, L.L.C., Andreessen Horowitz LSV Fund II, L.P., AH Equity Partners LSV II, L.L.C., Marc L. Andreessen, and Benjamin A. Horowitz.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/28/2026 - 07:44 PM Accepted by SEC EDGAR 08/28/2026 - 07:43 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. 3)

Nautilus Biotechnology, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

63909J108

(CUSIP Number)

a16z Capital Management
2865 Sand Hill Road, Suite 101,
Menlo Park, CA, 94025
(650) 798-5800

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

08/26/2026

(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

AH Bio Fund II, L.P.

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 7,094,691.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 7,094,691.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

7,094,691.00

12

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

13

Percent of class represented by amount in Row (11)

5.6 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

AH Equity Partners Bio II, L.L.C.

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 7,094,691.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 7,094,691.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

7,094,691.00

12

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

13

Percent of class represented by amount in Row (11)

5.6 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Andreessen Horowitz LSV Fund II, L.P.

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 590,241.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 590,241.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

590,241.00

12

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

13

Percent of class represented by amount in Row (11)

0.5 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

AH Equity Partners LSV II, L.L.C.

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 590,241.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 590,241.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

590,241.00

12

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

13

Percent of class represented by amount in Row (11)

0.5 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Marc L. Andreessen

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 7,684,932.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 7,684,932.00

11

Aggregate amount beneficially owned by each reporting person

7,684,932.00

12

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

13

Percent of class represented by amount in Row (11)

6.0 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP Number(s): 63909J108

1

Name of reporting person

Benjamin A. Horowitz

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 7,684,932.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 7,684,932.00

11

Aggregate amount beneficially owned by each reporting person

7,684,932.00

12

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

13

Percent of class represented by amount in Row (11)

6.0 %

14

Type of Reporting Person (See Instructions)

IN

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 1 Comment: This Amendment No. 3 (this "Amendment No. 3" or this "Schedule 13D/A") amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on June 30, 2021 and amended on June 4, 2026 and June 30, 2026 (as amended, the "Statement") by the Reporting Persons. Unless otherwise defined herein, capitalized terms used in this Amendment No. 3 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged.
Item 2.	Identity and Background
(a)	This Schedule 13D/A is filed by AH Bio Fund II, L.P. ("AH Bio II"), AH Equity Partners Bio II, L.L.C. ("AH Equity Bio II"), Andreessen Horowitz LSV Fund II, L.P. ("AH LSV II"), AH Equity Partners LSV II, L.L.C. ("AH Equity LSV II"), Marc Andreessen ("Andreessen") and Benjamin Horowitz ("Horowitz"). The foregoing entities and individuals are collectively referred to herein as the "Reporting Persons." The Reporting Persons' beneficial ownership of the Issuer's securities consists of (i) 7,094,691 shares of the Issuer's common stock directly held by AH Bio II for itself and as nominee for AH Bio Fund II-B, L.P. ("AH Bio II-B") and (ii) 590,241 shares of the Issuer's common stock directly held by AH LSV II for itself and as nominee for Andreessen Horowitz LSV Fund II-B, L.P. ("AH LSV II-B") and Andreessen Horowitz LSV Fund II-Q, L.P. ("AH LSV II-Q"). AH Equity Bio II is the general partner of AH Bio II and may be deemed to have sole power to vote and sole power to dispose of shares of the Issuer held of record by AH Bio II for itself and as nominee for AH Bio II-B. Andreessen and Horowitz are managing members of AH Equity Bio II and may be deemed to have shared power to vote and shared power to dispose of shares of the Issuer held of record by AH Bio II for itself and as nominee. AH Equity LSV II is the general partner of AH LSV II and may be deemed to have sole power to vote and sole power to dispose of shares of the Issuer held of record by AH LSV II for itself and as nominee for AH LSV II-B and AH LSV II-Q. Andreessen and Horowitz are managing members of AH Equity LSV II and may be deemed to have shared power to vote and shared power to dispose of shares of the Issuer held of record by AH LSV II for itself and as nominee.
(b)	The address of the principal place of business of each of the Reporting Persons is c/o Andreessen Horowitz, 2865 Sand Hill Road, Suite 101, Menlo Park, CA 94025.
(c)	The principal occupation of each of Andreessen and Horowitz is co-founder and managing member of the venture capital firm Andreessen Horowitz. The principal business of each of the other Reporting Persons is the venture capital investment business.
(d)	During the last five years, none of the Reporting Persons have been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the last five years, none of the Reporting Persons have been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.
(f)	The responses of the Reporting Persons with respect to row 6 of their respective cover pages to this Schedule 13D/A are incorporated herein by reference.
Item 5.	Interest in Securities of the Issuer
(a)	Rows 11 and 13 of each Reporting Person's cover page to this Schedule 13D/A set forth the aggregate number of shares of common stock of the Issuer and percentage of the shares of common stock of the Issuer beneficially owned by such Reporting Person and are incorporated herein by reference. The percentage set forth in row 13 of each cover page is based upon 127,255,223 shares of common stock outstanding as of July 24, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on July 28, 2026.
(b)	Rows 7 through 10 of each Reporting Person's cover page to this Schedule 13D/A set forth the number of shares of common stock of the Issuer as to which such Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition and are incorporated herein by reference.
(c)	Except as set forth below, none of the Reporting Persons has effected any transactions with respect to the securities of the Issuer during the past sixty days. Weighted Low High Reporting Transaction No. of Average Price Price Transaction Person Date Shares Price ($) ($) ($) Open Market Sale AH Bio II 07/31/2026 85,157 0.98 0.95 1.05 Open Market Sale AH LSV II 07/31/2026 7,085 0.98 0.95 1.05 Open Market Sale AH Bio II 08/03/2026 133,608 1.00 0.98 1.02 Open Market Sale AH LSV II 08/03/2026 11,116 1.00 0.98 1.02 Open Market Sale AH Bio II 08/04/2026 140,625 1.01 0.99 1.06 Open Market Sale AH LSV II 08/04/2026 11,699 1.01 0.99 1.06 Open Market Sale AH Bio II 08/05/2026 71,883 0.94 0.93 1.01 Open Market Sale AH LSV II 08/05/2026 5,980 0.94 0.93 1.01 Open Market Sale AH Bio II 08/10/2026 14,226 0.91 0.91 0.91 Open Market Sale AH LSV II 08/10/2026 1,184 0.91 0.91 0.91 Open Market Sale AH Bio II 08/11/2026 7,159 0.90 0.90 0.90 Open Market Sale AH LSV II 08/11/2026 596 0.90 0.90 0.90 Open Market Sale AH Bio II 08/12/2026 38,391 0.90 0.90 0.90 Open Market Sale AH LSV II 08/12/2026 3,194 0.90 0.90 0.90 Open Market Sale AH Bio II 08/13/2026 89,495 0.91 0.91 0.92 Open Market Sale AH LSV II 08/13/2026 7,445 0.91 0.91 0.92 Open Market Sale AH Bio II 08/14/2026 2,418 0.90 0.90 0.91 Open Market Sale AH LSV II 08/14/2026 201 0.90 0.90 0.91 Open Market Sale AH Bio II 08/17/2026 47,297 0.90 0.90 0.91 Open Market Sale AH LSV II 08/17/2026 3,935 0.90 0.90 0.91 Open Market Sale AH Bio II 08/19/2026 94,559 0.90 0.90 0.91 Open Market Sale AH LSV II 08/19/2026 7,867 0.90 0.90 0.91 Open Market Sale AH Bio II 08/20/2026 43,872 0.91 0.90 0.92 Open Market Sale AH LSV II 08/20/2026 3,650 0.91 0.90 0.92 Open Market Sale AH Bio II 08/21/2026 213,672 0.95 0.91 0.97 Open Market Sale AH LSV II 08/21/2026 17,776 0.95 0.91 0.97 Open Market Sale AH Bio II 08/25/2026 9,232 0.90 0.90 0.91 Open Market Sale AH LSV II 08/25/2026 768 0.90 0.90 0.91 Open Market Sale AH Bio II 08/26/2026 231,738 0.93 0.93 0.95 Open Market Sale AH LSV II 08/26/2026 19,279 0.93 0.93 0.95 Open Market Sale AH Bio II 08/27/2026 48,943 0.96 0.92 0.96 Open Market Sale AH LSV II 08/27/2026 4,072 0.96 0.92 0.96 Each of AH Bio II and AH LSV II undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth above.
(d)	Under certain circumstances set forth in the limited partnership agreement of each of AH Bio II, AH Bio II-B, AH LSV II, AH LSV II-B, AH LSV II-Q and the limited liability company agreement of each of AH Equity Bio II and AH Equity LSV II, the partners or members, as the case may be, of each of such entities may be deemed to have the right to receive dividends from, or the proceeds from the sale of, shares of the Issuer directly or indirectly owned by each such entity of which they are a partner or member.
(e)	Not applicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 24.1 Power of Attorney (Marc Andreessen), dated June 23, 2023 (incorporated by reference to Exhibit 24.1 to the amendment to the Statement filed with the SEC on June 4, 2026). Exhibit 24.2 Power of Attorney (Benjamin Horowitz), dated June 22, 2023 (incorporated by reference to Exhibit 24.2 to the amendment to the Statement filed with the SEC on June 4, 2026). Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to the amendment to the Statement filed with the SEC on June 4, 2026).

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.

AH Bio Fund II, L.P.

Signature:	/s/ Phil Hathaway
Name/Title:	By AH Equity Partners Bio II, L.L.C., Its General Partner, By Phil Hathaway, Chief Operating Officer (See Note 1)
Date:	08/28/2026

AH Equity Partners Bio II, L.L.C.

Signature:	/s/ Phil Hathaway
Name/Title:	By Phil Hathaway, Chief Operating Officer
Date:	08/28/2026

Andreessen Horowitz LSV Fund II, L.P.

Signature:	/s/ Phil Hathaway
Name/Title:	By AH Equity Partners LSV II, L.L.C., Its General Partner, By Phil Hathaway, Chief Operating Officer (See Note 2)
Date:	08/28/2026

AH Equity Partners LSV II, L.L.C.

Signature:	/s/ Phil Hathaway
Name/Title:	By Phil Hathaway, Chief Operating Officer
Date:	08/28/2026

Marc L. Andreessen

Signature:	/s/ Phil Hathaway
Name/Title:	By Phil Hathaway, Attorney-in-Fact for Marc Andreessen
Date:	08/28/2026

Benjamin A. Horowitz

Signature:	/s/ Phil Hathaway
Name/Title:	By Phil Hathaway, Attorney-in-Fact for Benjamin Horowitz
Date:	08/28/2026

Comments accompanying signature:

Note 1 AH Bio Fund II, L.P. for itself and as nominee for AH Bio Fund II-B, L.P. Note 2 Andreessen Horowitz LSV Fund II, L.P. for itself and as nominee for Andreessen Horowitz LSV Fund II-B, L.P. and Andreessen Horowitz LSV Fund II-Q, L.P.