Adaptive Biotechnologies CSO sells 42,788 shares

Adaptive Biotechnologies’ Chief Scientific Officer, Harlan S. Robins, reported preset stock sales under a Rule 10b5-1 trading plan.

Rhea-AI Filing Summary

Adaptive Biotechnologies’ Chief Scientific Officer, Harlan S. Robins, reported preset stock sales under a Rule 10b5-1 trading plan. On February 2, 2026, he sold 34,668 shares of common stock at a weighted average price of $18.60, followed by a sale of 8,120 shares on February 3, 2026 at a weighted average price of $19.00.

The filing notes these trades were executed under a trading plan adopted on August 11, 2025, and that each reported price reflects multiple trades within stated ranges. After these transactions, Robins beneficially owned 1,179,524 shares of Adaptive Biotechnologies common stock directly.

Insider Trade Summary

Net Seller: 42,788 shares

Net Sell 2 txns

Insider ROBINS HARLAN S

Role Chief Scientific Officer

Sold 42,788 shs ($799K)

Type	Security	Shares	Price	Value
Sale	Common Stock	8,120	$19.00	$154K
Sale	Common Stock	34,668	$18.60	$645K

Holdings After Transaction: Common Stock — 1,179,524 shares (Direct)

Footnotes (3)

1. F1. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 11, 2025.
2. F2. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.26 to $18.88, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4.
3. F3. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.56 to $19.38, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did ADPT disclose for Harlan S. Robins?

Adaptive Biotechnologies disclosed that Chief Scientific Officer Harlan S. Robins sold shares of common stock in two transactions on February 2 and 3, 2026, under a pre-established Rule 10b5-1 trading plan, while retaining over one million shares afterward.

How many Adaptive Biotechnologies (ADPT) shares did the CSO sell?

Harlan S. Robins sold 34,668 shares on February 2, 2026 and 8,120 shares on February 3, 2026. Both transactions involved Adaptive Biotechnologies common stock and were reported as open market sales under a Rule 10b5-1 trading plan.

What prices were received for the ADPT shares sold by the CSO?

The February 2, 2026 sale had a weighted average price of $18.60 per share, with individual trades ranging from $18.26 to $18.88. The February 3, 2026 sale had a weighted average price of $19.00, with trades ranging from $18.56 to $19.38.

How many ADPT shares does Harlan S. Robins still own after these sales?

Following the reported transactions, Harlan S. Robins beneficially owned 1,179,524 shares of Adaptive Biotechnologies common stock directly. This figure reflects his holdings after the February 2 and February 3, 2026 sales disclosed in the Form 4.

Were the ADPT insider sales made under a Rule 10b5-1 trading plan?

Yes. The filing states the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by Harlan S. Robins on August 11, 2025. Such plans allow insiders to schedule trades in advance under predetermined instructions.

What do the weighted average prices in the ADPT Form 4 mean?

The weighted average prices reflect multiple trades executed within specified price ranges on each day. For each transaction, Robins undertakes to provide full details of the number of shares sold at each individual price to the company, its security holders, or the SEC upon request.

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

Form 4 Insider Transactions: What Each Field Means →

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Accepted by SEC EDGAR 02/04/2026 - 07:48 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

ROBINS HARLAN S

(Last) (First) (Middle)

C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION

1165 EASTLAKE AVE E

(Street)

SEATTLE WA 98109

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Adaptive Biotechnologies Corp [ ADPT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/02/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/02/2026		S(1)		34,668	D	$18.6(2)	1,187,644	D
Common Stock	02/03/2026		S(1)		8,120	D	$19(3)	1,179,524	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 11, 2025.

2. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.26 to $18.88, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4.

3. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.56 to $19.38, inclusive. The reporting person undertakes to provide to Adaptive Biotechnologies Corporation, any security holder of Adaptive Biotechnologies Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in any footnotes to this Form 4.

	/s/ Harlan S. Robins by Kyle Piskel, Attorney-in-Fact	02/04/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.