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Atara Biotherapeutics (ATRA) director affiliate exercises pre-funded warrants

(Neutral)
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Funds managed by Redmile Group, LLC exercised Atara Biotherapeutics pre-funded warrants on July 22, 2026 via a cashless exercise. The exercise delivered 195,211 shares of common stock to the funds, with 60 shares withheld to cover the exercise price. The funds continue to hold pre-funded warrants with low exercise prices ($0.0025 and $0.0001 per share), each limited by a 9.99% beneficial ownership blocker. Redmile and Jeremy Green report these as indirect holdings, disclaiming beneficial ownership beyond their pecuniary interest, and also correct prior warrant terms previously reported.

Positive

  • None.

Negative

  • None.
Insider Redmile Group, LLC, Green Jeremy
Role Director | Director
Type Security Shares Price Value
Exercise Pre-Funded Warrants to Purchase Common Stock F1, F8, F5, F4 101,089 $0.00 $0.00
Exercise Pre-Funded Warrants to Purchase Common Stock F2, F8, F5, F4 38,735 $0.00 $0.00
Exercise Pre-Funded Warrants to Purchase Common Stock F3, F8, F5, F4 55,387 $0.00 $0.00
Exercise Common Stock F5, F4 195,211 -- --
Exercise Price or Tax Liability Common Stock F5, F4 60 -- --
holding Pre-Funded Warrants to Purchase Common Stock F6, F8, F4 -- -- --
holding Pre-Funded Warrants to Purchase Common Stock F7, F8, F4 -- -- --
Holdings After Transaction: Pre-Funded Warrants to Purchase Common Stock — 3,217,632 shares (Indirect, See Footnote); Common Stock — 636,852 shares (Indirect, See Footnote)
Footnotes (8)
  1. F1. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on July 23, 2019 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
  2. F2. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on May 29, 2020 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
  3. F3. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on December 11, 2020 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
  4. F4. The reported securities are directly owned by certain private funds managed by Redmile Group, LLC (collectively, the "Funds") and may be deemed beneficially owned by Redmile Group, LLC ("Redmile") as investment manager of the Funds. The reported securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. Each of Redmile and Mr. Green (the "Reporting Persons") disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, if any. This report shall not be deemed an admission that such Reporting Persons are the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
  5. F5. On July 22, 2026, the Reporting Persons exercised the reported Pre-Funded Warrants through a "cashless exercise" resulting in the Issuer withholding 60 shares of Common Stock to pay the exercise price and issuing the remaining 195,151 shares of Common Stock to the applicable Funds. The number of shares withheld to pay the aggregate exercise price for the cashless exercise of the Pre-Funded Warrants was based on the closing sale price per share of the Common Stock on the trading date immediately prior to the exercise date, per the terms of the Pre-Funded Warrants.
  6. F6. The Pre-Funded Warrants are exercisable at any time on or after the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker. The Pre-Funded Warrants have no expiration date.
  7. F7. The Pre-Funded Warrants are exercisable at any time on or after the original issuance date, at an exercise price equal to $0.0001 per share, subject to a 9.99% beneficial ownership blocker. The Pre-Funded Warrants have no expiration date.
  8. F8. The previous report on Form 3 inadvertently indicated that all of the Pre-Funded Warrants beneficially owned by the Reporting Persons have an exercise price of $0.0001 per share and no expiration date. Footnotes (1), (2), (3), (6) and (7) and the related disclosures correct the Form 3 with respect to the terms of the Pre-Funded Warrants beneficially owned by the Reporting Persons.
Common shares received 195,211 shares Shares of Atara common stock issued to Redmile-managed funds upon cashless warrant exercise on July 22, 2026
Shares withheld for exercise price 60 shares Common shares withheld by issuer to pay aggregate exercise price in the cashless exercise
Warrants exercised (tranche 1) 101,089 pre-funded warrants Pre-funded warrants to purchase common stock exercised on July 22, 2026 at $0.0025 per share
Warrants exercised (tranche 2) 38,735 pre-funded warrants Additional pre-funded warrants exercised on July 22, 2026 at $0.0025 per share
Warrants exercised (tranche 3) 55,387 pre-funded warrants Additional pre-funded warrants exercised on July 22, 2026 at $0.0025 per share
Remaining warrants at $0.0025 1,090,907 underlying shares Pre-funded warrants still outstanding, exercisable at $0.0025 per share, subject to 9.99% beneficial ownership cap
Remaining warrants at $0.0001 2,126,725 underlying shares Pre-funded warrants still outstanding, exercisable at $0.0001 per share, subject to 9.99% beneficial ownership cap
Beneficial ownership blocker 9.99% Cap on ownership for pre-funded warrants to limit beneficial ownership percentage upon exercise
Pre-Funded Warrants financial
"The Pre-Funded Warrants are exercisable at any time on or after the original issuance"
Pre-funded warrants are financial instruments that give investors the right to purchase a company's stock at a set price, but with most or all of the purchase price paid upfront. They function like a coupon or gift card for stock, allowing investors to buy shares later at a fixed price, which can be beneficial if they want to avoid future price increases. This makes them important for investors seeking flexibility and certainty in their investment plans.
cashless exercise financial
"exercised the reported Pre-Funded Warrants through a "cashless exercise" resulting in the Issuer"
A cashless exercise is a way for an option holder to convert stock options into actual shares without paying the purchase price in cash; instead they immediately give up a portion of the newly issued shares to cover the cost and any withholding taxes. Investors care because this process increases the number of shares available and can slightly dilute existing holdings, while also signaling how insiders or employees are realizing compensation without needing cash — similar to paying for a purchase by handing over part of what you just bought.
beneficial ownership blocker regulatory
"at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker"
A beneficial ownership blocker is a legal or structural device that prevents a shareholder from being treated as the ultimate owner of enough shares to trigger control, reporting, or voting thresholds. Think of it like a speed bump that stops an investor from reaching a stake size that would force corporate disclosure or change control rights. Investors care because it affects who controls the company, how shares vote, regulatory filings, takeover risk and therefore potential value or liquidity of their holdings.
directors by deputization regulatory
"the Reporting Persons are directors by deputization for purposes of Section 16"
pecuniary interest financial
"disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest"

AI-generated analysis. How Rhea-AI works. Not financial advice.

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FAQ

What insider transaction did Redmile Group report for Atara Biotherapeutics (ATRA)?

Redmile-managed funds exercised pre-funded warrants in Atara Biotherapeutics via a cashless exercise, receiving 195,211 shares of common stock while 60 shares were withheld to pay the aggregate exercise price under the warrant terms.

How were the Atara Biotherapeutics (ATRA) pre-funded warrants exercised by Redmile?

The warrants were exercised through a cashless exercise, meaning no cash changed hands. Instead, Atara withheld 60 shares of common stock to cover the exercise price and issued 195,211 shares of common stock to the Redmile-managed funds.

What pre-funded warrant positions do Redmile-managed funds still hold in Atara Biotherapeutics (ATRA)?

After this exercise, the funds still report pre-funded warrants convertible into 1,090,907 shares at an exercise price of $0.0025 and 2,126,725 shares at $0.0001 per share, each subject to a 9.99% beneficial ownership blocker.

Were the Atara Biotherapeutics (ATRA) Form 4 transactions under a Rule 10b5-1 plan?

No. The Form 4’s Rule 10b5-1 checkbox is not marked, and there is no footnote indicating a trading plan. The reported derivative exercises and share withholding therefore are not identified as occurring under a pre-arranged Rule 10b5-1 trading plan.

How is ownership of the Atara Biotherapeutics (ATRA) securities attributed between Redmile and Jeremy Green?

The securities are directly owned by private funds managed by Redmile Group, LLC. Redmile and Jeremy Green may be deemed beneficial owners as investment manager and principal, but they disclaim beneficial ownership except to the extent of any pecuniary interest.

What correction to earlier disclosures about Atara Biotherapeutics (ATRA) warrants was made?

A footnote explains that a prior Form 3 incorrectly showed all pre-funded warrants as having a $0.0001 exercise price and no expiration. The current disclosure corrects the warrant terms, distinguishing between $0.0025 and $0.0001 exercise prices and differing expirations.
SEC Form 4
FORM 4UNITED 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).
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*
Redmile Group, LLC

(Last)(First)(Middle)
900 LARKSPUR LANDING CIRCLE
SUITE 270

(Street)
LARKSPUR CALIFORNIA 94939

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Atara Biotherapeutics, Inc. [ ATRA ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
07/22/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock07/22/2026M(5)195,211A(5)636,912ISee Footnote(4)
Common Stock07/22/2026F(5)60D(5)636,852ISee Footnote(4)
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Pre-Funded Warrants to Purchase Common Stock$0.0025(1)(8)07/22/2026M(5)101,089 (1)(8) (1)(8)Common Stock101,089$0.000ISee Footnote(4)
Pre-Funded Warrants to Purchase Common Stock$0.0025(2)(8)07/22/2026M(5)38,735 (2)(8) (2)(8)Common Stock38,735$0.000ISee Footnote(4)
Pre-Funded Warrants to Purchase Common Stock$0.0025(3)(8)07/22/2026M(5)55,387 (3)(8) (3)(8)Common Stock55,387$0.000ISee Footnote(4)
Pre-Funded Warrants to Purchase Common Stock$0.0025(6)(8) (6)(8) (6)(8)Common Stock1,090,9071,090,907ISee Footnote(4)
Pre-Funded Warrants to Purchase Common Stock$0.0001(7)(8) (7)(8) (7)(8)Common Stock2,126,7252,126,725ISee Footnote(4)
1. Name and Address of Reporting Person*
Redmile Group, LLC

(Last)(First)(Middle)
900 LARKSPUR LANDING CIRCLE
SUITE 270

(Street)
LARKSPUR CALIFORNIA 94939

(City)(State)(Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
1. Name and Address of Reporting Person*
Green Jeremy

(Last)(First)(Middle)
C/O REDMILE GROUP, LLC (NY OFFICE)
45 W. 27TH STREET, FLOOR 11

(Street)
NEW YORK NEW YORK 10001

(City)(State)(Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer
XDirector10% Owner
Officer (give title below)Other (specify below)
Explanation of Responses:
1. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on July 23, 2019 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
2. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on May 29, 2020 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
3. The Pre-Funded Warrants are exercisable at any time on or after the original issuance on December 11, 2020 until the seven-year anniversary of the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker.
4. The reported securities are directly owned by certain private funds managed by Redmile Group, LLC (collectively, the "Funds") and may be deemed beneficially owned by Redmile Group, LLC ("Redmile") as investment manager of the Funds. The reported securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. Each of Redmile and Mr. Green (the "Reporting Persons") disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, if any. This report shall not be deemed an admission that such Reporting Persons are the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
5. On July 22, 2026, the Reporting Persons exercised the reported Pre-Funded Warrants through a "cashless exercise" resulting in the Issuer withholding 60 shares of Common Stock to pay the exercise price and issuing the remaining 195,151 shares of Common Stock to the applicable Funds. The number of shares withheld to pay the aggregate exercise price for the cashless exercise of the Pre-Funded Warrants was based on the closing sale price per share of the Common Stock on the trading date immediately prior to the exercise date, per the terms of the Pre-Funded Warrants.
6. The Pre-Funded Warrants are exercisable at any time on or after the original issuance date, at an exercise price equal to $0.0025 per share, subject to a 9.99% beneficial ownership blocker. The Pre-Funded Warrants have no expiration date.
7. The Pre-Funded Warrants are exercisable at any time on or after the original issuance date, at an exercise price equal to $0.0001 per share, subject to a 9.99% beneficial ownership blocker. The Pre-Funded Warrants have no expiration date.
8. The previous report on Form 3 inadvertently indicated that all of the Pre-Funded Warrants beneficially owned by the Reporting Persons have an exercise price of $0.0001 per share and no expiration date. Footnotes (1), (2), (3), (6) and (7) and the related disclosures correct the Form 3 with respect to the terms of the Pre-Funded Warrants beneficially owned by the Reporting Persons.
Remarks:
Mr. Nachi Subramanian, a member of the board of directors of the Issuer and a managing director of Redmile, was elected to the board of the Issuer as a representative of Redmile and its affiliates. As a result, the Reporting Persons are directors by deputization for purposes of Section 16 of the Securities Exchange Act of 1934, as amended.
By: /s/ Jeremy Green, Managing Member of Redmile Group, LLC07/24/2026
/s/ Jeremy Green07/24/2026
** Signature of Reporting PersonDate
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)