Adaptive Biotechnologies (ADPT) CEO sells shares to cover tax withholding

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp CEO and Chairman Chad M. Robins reported mandated share sales tied to equity award vesting. On March 11, 2026, he sold a total of 470,167 shares of Common Stock at $13.17 per share in open-market transactions.

Footnotes explain these sales were required to cover tax withholding obligations from vesting RSUs and performance share units under the company’s equity incentive plans, and they were not discretionary trades. After these transactions, Robins directly holds 2,301,113 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

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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).

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 CHAD M

(Last) (First) (Middle)

C/O ADAPTIVE BIOTECHNOLOGIES CORPORATION

1165 EASTLAKE AVENUE EAST

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO and Chairman

3. Date of Earliest Transaction (Month/Day/Year)
03/11/2026

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	03/11/2026		S(1)		140,567	D	$13.17	2,630,713	D
Common Stock	03/11/2026		S(2)		329,600	D	$13.17	2,301,113	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. This transaction represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.

2. This transaction represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of performance share units. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.

	/s/ Chad M Robins by Kyle Piskel, Attorney-in-Fact	03/13/2026
	** 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).
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FAQ

What insider transaction did Adaptive Biotechnologies (ADPT) CEO Chad Robins report?

CEO Chad Robins reported mandated sales of 470,167 shares of Adaptive Biotechnologies Common Stock. The shares were sold at $13.17 per share on March 11, 2026 to satisfy tax withholding obligations related to vesting RSUs and performance share units.

Why did the ADPT CEO sell 470,167 shares in the latest Form 4?

The 470,167 shares sold by CEO Chad Robins were to cover tax withholding obligations from vesting RSUs and performance share units. Footnotes state these "sell to cover" transactions were mandated under the company’s equity incentive plans and were not discretionary trades.

At what price were Chad Robins’ Adaptive Biotechnologies shares sold?

Chad Robins’ reported sales occurred at an average price of $13.17 per share. The Form 4 shows two open-market sale transactions on March 11, 2026, both priced at $13.17, executed solely to fund required tax withholding on equity award vesting.

How many Adaptive Biotechnologies shares does the CEO hold after these sales?

Following the reported transactions, CEO Chad Robins directly holds 2,301,113 shares of Adaptive Biotechnologies Common Stock. This post-transaction figure reflects his remaining direct ownership after the mandated tax-related sales totaling 470,167 shares on March 11, 2026.

Were the recent ADPT CEO share sales discretionary or part of a tax obligation?

The sales were part of a tax obligation, not discretionary. Footnotes clarify the transactions were "sell to cover" trades required to satisfy tax withholding on vesting RSUs and performance share units under the company’s equity incentive plans.