SEC FORM 3

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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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1. Name and Address of Reporting Person^*

Hyllengren Eric J

(Last)

(First)

(Middle)

C/O ATARA BIOTHERAPEUTICS, INC.

2380 CONEJO SPECTRUM STREET, SUITE 200

(Street)

THOUSAND OAKS

91320

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2023

3. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ ATRA ]

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

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	SVP, CFO

5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	234,060⁽¹⁾⁽²⁾	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Employee Stock Option (Right to Buy)	08/20/2022	09/03/2025	Common Stock	47,500	$39.85	D
Employee Stock Option (Right to Buy)	02/06/2023	02/05/2029	Common Stock	11,500	$38.47	D
Employee Stock Option (Right to Buy)	04/01/2023	02/28/2030	Common Stock	12,526	$12.15	D
Employee Stock Option (Right to Buy)	⁽³⁾	02/28/2030	Common Stock	3,724	$12.15	D
Employee Stock Option (Right to Buy)	04/01/2023	02/28/2031	Common Stock	9,530	$17.105	D
Employee Stock Option (Right to Buy)	⁽⁴⁾	02/28/2031	Common Stock	8,768	$17.105	D
Employee Stock Option (Right to Buy)	04/01/2023	02/29/2032	Common Stock	6,540	$10.21	D
Employee Stock Option (Right to Buy)	⁽⁵⁾	02/29/2032	Common Stock	17,608	$10.21	D
Employee Stock Option (Right to Buy)	04/01/2023	02/28/2033	Common Stock	8,298	$3.91	D
Employee Stock Option (Right to Buy)	⁽⁵⁾	02/28/2033	Common Stock	290,417	$3.91	D

Explanation of Responses:

1. Includes an aggregate 194,599 restricted stock units ("RSUs"), which are comprised of: (i) 5,297 RSUs that vest as to 1/4th of the shares on May 15, 2023 and each of the next three (3) "Quarterly Vesting Dates" (as defined herein); (ii) 6,066 RSUs that vest as to 1/8th of shares on May 15, 2023 and each of the next seven (7) Quarterly Vesting Dates; (iii) 18,697 RSUs that vest as to 1/3rd of shares on November 15, 2023, November 15, 2024 and November 15, 2025; (iv) 11,777 RSUs that vest as to 1/12th of shares on May 15, 2023 and each of the next eleven (11) Quarterly Vesting Dates; (v) 20,000 RSUs that vest as to 1/2nd of shares on November 15, 2023 and 1/2nd on November 15, 2024; and (vi) 132,762 RSUs that vest as to 1/12th of shares on May 15, 2023 and each of the next eleven (11) Quarterly Vesting Dates, each of which is subject to the reporting person's continuous service.

2. "Quarterly Vesting Date" means March 1, May 15, August 15, and November 15 of each year, provided that if such date falls on a weekend or holiday, the "Quarterly Vesting Date" shall be the first (1st) business day after such date.

3. 1/11th of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following ten (10) months, subject to the reporting person's continuous service.

4. 1/23rd of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following twenty-two (22) months, subject to the reporting person's continuous service.

5. 1/35th of shares subject to the stock option vest and become exercisable on May 1, 2023, and the remaining shares vest in equal monthly installments over the following thirty-four (34) months, subject to the reporting person's continuous service.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Jeff Kiekhofer, Attorney-in-Fact for Eric J. Hyllengren	04/07/2023
	** 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 5 (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.
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