Adaptive Biotechnologies (ADPT) COO sells 179,703 shares under 10b5-1 plan

Rhea-AI Filing Summary

Adaptive Biotechnologies President and COO Julie Rubinstein reported a series of option exercises and stock sales. She exercised options to acquire 44,166 shares of common stock at an exercise price of $6.55 per share and sold 179,703 shares in multiple open-market transactions, including sales at $12.63, $12.96, $13.17, $13.43 and $14.08 per share. A portion of the shares sold was mandated to cover tax withholding on RSU vesting, and all transactions were carried out under a Rule 10b5-1 trading plan. After these transactions, she directly holds 507,934 shares of common stock and retains 62,827 fully vested stock options exercisable at $6.55 per share expiring on February 7, 2028.

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

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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^*

RUBINSTEIN JULIE

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and COO

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)		122,523	D	$13.17	520,948	D
Common Stock	03/11/2026		M(2)		14,722	A	$6.55	535,670	D
Common Stock	03/11/2026		S(2)		19,060	D	$14.08(3)	516,610	D
Common Stock	03/12/2026		M(2)		14,722	A	$6.55	531,332	D
Common Stock	03/12/2026		S(2)		13,660	D	$12.63(4)	517,672	D
Common Stock	03/12/2026		S(2)		5,400	D	$13.43(5)	512,272	D
Common Stock	03/13/2026		M(2)		14,722	A	$6.55	526,994	D
Common Stock	03/13/2026		S(2)		19,060	D	$12.96(6)	507,934	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
Stock Option (right to buy)	$6.55	03/11/2026		M(2)			14,722	(7)	02/07/2028	Common Stock	14,722	$0	92,271	D
Stock Option (right to buy)	$6.55	03/12/2026		M(2)			14,722	(7)	02/07/2028	Common Stock	14,722	$0	77,549	D
Stock Option (right to buy)	$6.55	03/13/2026		M(2)			14,722	(7)	02/07/2028	Common Stock	14,722	$0	62,827	D

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 Issuer's election under the 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. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 18, 2025.

3. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.83 to $14.38, 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.

4. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.11 to $13.02, 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.

5. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.12 to $13.76, 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.

6. The price reported for this transaction is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.76 to $13.19, 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.

7. The option is fully vested and exercisable.

	/s/ Julie Rubinstein 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.
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FAQ

What insider transactions did Adaptive Biotechnologies (ADPT) report for Julie Rubinstein?

Julie Rubinstein exercised options and sold shares. She exercised options for 44,166 shares at $6.55 per share and sold 179,703 common shares in several open-market trades while remaining a significant direct shareholder in Adaptive Biotechnologies.

How many Adaptive Biotechnologies (ADPT) shares did the COO sell and at what prices?

The COO sold 179,703 shares of common stock. These open-market sales occurred at various prices, including $12.63, $12.96, $13.17, $13.43 and $14.08 per share, as part of a broader set of planned transactions.

Did Julie Rubinstein of Adaptive Biotechnologies (ADPT) exercise stock options in this Form 4?

Yes, she exercised stock options. Rubinstein exercised options to acquire 44,166 shares of Adaptive Biotechnologies common stock at an exercise price of $6.55 per share, converting derivative awards into directly held common shares.

How many Adaptive Biotechnologies (ADPT) shares does the COO hold after these transactions?

After the reported trades, she holds 507,934 shares. These are directly owned shares of Adaptive Biotechnologies common stock, reflecting her continuing equity stake following the combination of option exercises and open-market sales.

Were the Adaptive Biotechnologies (ADPT) insider sales by the COO discretionary?

Not entirely; some were mandated. A portion of the shares sold covered tax withholding obligations from RSU vesting, and all transactions were executed under a pre-established Rule 10b5-1 trading plan adopted on November 18, 2025.

Does the Adaptive Biotechnologies (ADPT) COO still hold stock options after these transactions?

Yes, she retains vested stock options. Following the exercises reported, Rubinstein still holds 62,827 fully vested options with a $6.55 exercise price, expiring on February 7, 2028, providing additional potential future share ownership.