Adaptive Biotechnologies (NASDAQ: ADPT) CSO sells 10,000 shares under 10b5-1 plan

Rhea-AI Filing Summary

Adaptive Biotechnologies Corp Chief Scientific Officer Harlan S. Robins reported an open-market sale of 10,000 shares of common stock on April 8, 2026 at a weighted-average price of $14.85 per share. The trades were executed under a pre-arranged Rule 10b5-1 trading plan adopted on August 11, 2025. Following this transaction, Robins directly holds 1,512,058 shares of Adaptive Biotechnologies common stock.

Insider Trade Summary 10b5-1

Net Seller: 10,000 shares ($148,500)

Net Sell 1 txn

Insider ROBINS HARLAN S

Role Chief Scientific Officer

Sold 10,000 shs ($149K)

Type	Security	Shares	Price	Value
Sale	Common Stock	10,000	$14.85	$149K

Holdings After Transaction: Common Stock — 1,512,058 shares (Direct)

Footnotes (1)

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. The price reported for this transaction is a weighted-average price. The shares were sold in multiple transactions ranging from $14.65 to $15.06, 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.

Key Figures

Shares sold: 10,000 shares Weighted-average sale price: $14.85 per share Post-transaction holdings: 1,512,058 shares +1 more

4 metrics

Shares sold 10,000 shares Open-market sale on April 8, 2026

Weighted-average sale price $14.85 per share Common stock sale on April 8, 2026

Post-transaction holdings 1,512,058 shares Shares directly owned after the sale

Transaction price range $14.65–$15.06 per share Multiple trades included in the 10,000-share sale

Key Terms

Rule 10b5-1 trading plan, weighted-average price, open-market sale

3 terms

Rule 10b5-1 trading plan financial

"The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted-average price financial

"The price reported for this transaction is a weighted-average price."

open-market sale financial

"transaction_action: "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Form 4 Insider Transactions: What Each Field Means →

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 AVENUE EAST

(Street)

SEATTLE WASHINGTON 98109

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/08/2026

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

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

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

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	04/08/2026		S(1)		10,000	D	$14.85(2)	1,512,058	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. The shares were sold in multiple transactions ranging from $14.65 to $15.06, 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	04/10/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

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

Adaptive Biotechnologies reported that Chief Scientific Officer Harlan S. Robins sold 10,000 shares of common stock in an open-market transaction. The sale occurred on April 8, 2026 at a weighted-average price of $14.85 per share and was executed under a Rule 10b5-1 plan.

At what price did Harlan S. Robins sell Adaptive Biotechnologies (ADPT) shares?

Harlan S. Robins sold 10,000 Adaptive Biotechnologies shares at a weighted-average price of $14.85 per share. According to the filing, individual trades were executed in multiple transactions with prices ranging from $14.65 to $15.06 per share, inclusive, on April 8, 2026.

How many Adaptive Biotechnologies (ADPT) shares does Harlan S. Robins own after this Form 4 sale?

After the reported sale, Harlan S. Robins directly owns 1,512,058 shares of Adaptive Biotechnologies common stock. This figure reflects his holdings immediately following the 10,000-share open-market sale disclosed for April 8, 2026 in the Form 4 filing.

Was the Adaptive Biotechnologies (ADPT) insider sale by Harlan S. Robins part of a trading plan?

Yes. The Form 4 states that the transactions were effected under a Rule 10b5-1 trading plan adopted by Harlan S. Robins on August 11, 2025. Such plans allow pre-scheduled trades, helping insiders systematically sell shares over time under predefined conditions.

What does the price range in Harlan S. Robins’ Adaptive Biotechnologies (ADPT) sale indicate?

The filing notes a weighted-average price of $14.85, with actual trades ranging from $14.65 to $15.06 per share. This means the 10,000 shares were sold in multiple transactions within that range, and detailed per-trade pricing is available from the issuer upon request.