Adaptive Biotechnologies (ADPT) CSO sells 24,233 shares in planned trades

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp’s Chief Scientific Officer, Harlan S. Robins, reported open-market sales of company common stock under a pre-established Rule 10b5-1 trading plan adopted on August 11, 2025.

He sold 10,000 shares on March 2, 2026 at a weighted average price of $15.72 per share and 14,233 shares on March 3, 2026 at a weighted average price of $16.52 per share. After these sales, he directly owned 1,155,291 shares of Adaptive Biotechnologies common stock.

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
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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)
03/02/2026

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	03/02/2026		S(1)		10,000	D	$15.72(2)	1,169,524	D
Common Stock	03/03/2026		S(1)		14,233	D	$16.52(3)	1,155,291	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 $15.57 to $15.88, 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 $16.50 to $16.55, 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	03/04/2026
	** 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.

FAQ

What insider transaction did Adaptive Biotechnologies (ADPT) report for Harlan S. Robins?

Adaptive Biotechnologies reported that Chief Scientific Officer Harlan S. Robins sold 24,233 shares of common stock in open-market transactions. These trades occurred on March 2 and March 3, 2026 under a pre-arranged Rule 10b5-1 trading plan.

How many Adaptive Biotechnologies (ADPT) shares did Harlan S. Robins sell and on which dates?

Harlan S. Robins sold a total of 24,233 Adaptive Biotechnologies common shares. He sold 10,000 shares on March 2, 2026 and 14,233 shares on March 3, 2026, according to the Form 4 insider trading report.

At what prices were the Adaptive Biotechnologies (ADPT) shares sold by Harlan S. Robins?

The reported sales used weighted average prices of $15.72 per share on March 2, 2026 and $16.52 per share on March 3, 2026. Footnotes note each day’s trades occurred across multiple prices within narrow ranges.

Did Harlan S. Robins’ Adaptive Biotechnologies (ADPT) stock sales occur under a trading plan?

Yes. The Form 4 states the transactions were effected under a Rule 10b5-1 trading plan adopted by Harlan S. Robins on August 11, 2025. Such plans pre-schedule trades to help manage insider trading concerns.

How many Adaptive Biotechnologies (ADPT) shares does Harlan S. Robins hold after these sales?

Following the reported transactions, Harlan S. Robins directly owned 1,155,291 shares of Adaptive Biotechnologies common stock. This post-transaction holding reflects his remaining equity stake after selling a combined 24,233 shares in early March 2026.

What type of insider is Harlan S. Robins at Adaptive Biotechnologies (ADPT)?

Harlan S. Robins is identified as an officer of Adaptive Biotechnologies, serving as Chief Scientific Officer. As an executive, his trades in the company’s common stock must be reported on Form 4 under insider trading disclosure rules.