OmniAb, Inc. received an updated Schedule 13G/A showing that several related investment entities and individuals collectively hold meaningful passive stakes in its common stock. As of December 31, 2025, Robert Goldstein may have been deemed to beneficially own approximately 8.5% of OmniAb’s common shares, or 12,291,972 shares, through direct holdings and control positions in various entities. Ash X LP and its general partner RLG GP LLC each may have been deemed to beneficially own 7,557,202 shares, or about 5.3% of the company. RLG Capco II LLC may have been deemed to beneficially own 4,733,575 shares, or about 3.3%. Joel Greenblatt may have been deemed to beneficially own 1,429,766 shares, or about 1.0%. All percentages are based on 143,955,400 shares outstanding as of October 28, 2025. The reporting group certifies the holdings are in the ordinary course of business and not for the purpose of changing or influencing control of OmniAb.
Positive
None.
Negative
None.
Insights
Filers report an 8.5% passive OmniAb stake without stated control intent.
The filing shows entities affiliated with Robert Goldstein and Joel Greenblatt holding sizeable positions in OmniAb common stock. Goldstein may have been deemed to beneficially own 12,291,972 shares, or about 8.5%, while Ash X and RLG GP each report about 5.3%.
These positions are spread across a limited partnership (Ash X), related LLCs, a managed account advised by Gotham Asset Management, LLC, and direct personal holdings. The structure concentrates voting and dispositive power, with Goldstein and, to a lesser extent, Greenblatt connected through management roles.
The certification states the securities were acquired and are held in the ordinary course of business and not to change or influence control, indicating a passive investment posture under December 31, 2025 ownership levels. Future ownership updates in regulatory filings would clarify whether these stakes increase, decrease, or remain stable over time.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 2)
OmniAb, Inc.
(Name of Issuer)
Common Stock, par value $0.0001 per share
(Title of Class of Securities)
68218J103
(CUSIP Number)
12/31/2025
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Ash X LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
7,557,202.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
7,557,202.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
7,557,202.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.3 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
RLG GP LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
7,557,202.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
7,557,202.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
7,557,202.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.3 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
RLG Capco II LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
4,733,575.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
4,733,575.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,733,575.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
3.3 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Gotham Asset Management, LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
1,195.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
1,195.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,195.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
IA, OO
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Gotham Asset Management Holdings, LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
1,195.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
1,195.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,195.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
HC, PN
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Gotham GP LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
1,195.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
1,195.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,195.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
OO, HC
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Robert Goldstein
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
12,290,777.00
6
Shared Voting Power
1,195.00
7
Sole Dispositive Power
12,290,777.00
8
Shared Dispositive Power
1,195.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
12,291,972.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
8.5 %
12
Type of Reporting Person (See Instructions)
IN, HC
SCHEDULE 13G
CUSIP No.
68218J103
1
Names of Reporting Persons
Joel Greenblatt
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
1,428,571.00
6
Shared Voting Power
1,195.00
7
Sole Dispositive Power
1,428,571.00
8
Shared Dispositive Power
1,195.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,429,766.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
1 %
12
Type of Reporting Person (See Instructions)
IN, HC
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
OmniAb, Inc.
(b)
Address of issuer's principal executive offices:
5980 Horton Street, Suite 600, Emeryville, California, 94608
Item 2.
(a)
Name of person filing:
(i) Ash X LP ("Ash X"), (ii) RLG GP LLC ("RLG GP"), (iii) RLG Capco II LLC ("RLG Capco II"), (iv) Gotham Asset Management, LLC (the "Adviser"), (v) Gotham Asset Management Holdings, LP ("Gotham Parent"), (vi) Gotham GP LLC ("GP of Gotham Parent"), (vii) Robert Goldstein, and (viii) Joel Greenblatt (collectively, the "Reporting Persons")
(b)
Address or principal business office or, if none, residence:
For each of the Reporting Persons: 825 Third Avenue, Floor 17, New York, New York 10022.
(c)
Citizenship:
(i) Ash X is a Delaware limited partnership, (ii) RLG GP is a Delaware limited liability company, (iii) RLG Capco II is a Delaware limited liability company, (iv) the Adviser is a Delaware limited liability company, (v) Gotham Parent is a Delaware limited partnership, (vi) GP of Gotham Parent is a Delaware limited liability company, (vii) Robert Goldstein is a United States citizen, and (viii) Joel Greenblatt is a United States citizen.
(d)
Title of class of securities:
Common Stock, par value $0.0001 per share
(e)
CUSIP No.:
68218J103
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
As of December 31, 2025, Ash X was the direct holder and beneficial owner of 7,557,202 shares of Common Stock, par value $0.0001 per share ("Common Stock") of OmniAB, Inc. (the "Issuer"). As the General Partner of Ash X, RLG GP may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by Ash X and thus may have been deemed to have beneficially owned such shares of Common Stock. As the Managing Member of RLG GP, Robert Goldstein may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by Ash X and thus may have been deemed to have beneficially owned such shares of Common Stock. As of December 31, 2025, RLG Capco II was the direct holder and beneficial owner of 4,733,575 shares of Common Stock of the Issuer. As the Manager of RLG Capco II, Robert Goldstein may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were held directly by RLG Capco II and thus may have been deemed to have beneficially owned such shares of Common Stock. As of December 31, 2025, a certain managed account (the "Account") for which the Adviser serves as investment manager was the direct holder of 1,195 shares of Common Stock. As the investment manager for the Account, the Adviser may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by the Account and thus may have been deemed to have beneficially owned such shares of Common Stock. As the sole owner of the Adviser, Gotham Parent may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by the Account and thus may have been deemed to have beneficially owned such shares of Common Stock. As the general partner of Gotham Parent, GP of Gotham Parent may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by the Account and thus may have been deemed to have beneficially owned such shares of Common Stock. As the members and managers of GP of Gotham Parent, Robert Goldstein and Joel Greenblatt may have been deemed to have exercised voting and investment power over such shares of Common Stock of the Issuer that were directly held by the Account and thus may have been deemed to have beneficially owned such shares of Common Stock. As of December 31, 2025, Joel Greenblatt was the direct holder and beneficial owner of 1,428,571 shares of Common Stock.
(b)
Percent of class:
As of December 31, 2025, Ash X and RLG GP may have been deemed to have each beneficially owned approximately 5.3% of the shares of Common Stock of the Issuer outstanding. As of December 31, 2025, RLG Capco II may have been deemed to have beneficially owned approximately 3.3% of the shares of Common Stock of the Issuer outstanding. As of December 31, 2025, the Adviser, Gotham Parent and GP of Gotham Parent may have been deemed to have each beneficially owned less than 1% of the shares of Common Stock outstanding. As of December 31, 2025, Robert Goldstein may have been deemed to have beneficially owned approximately 8.5% of the shares of Common Stock of the Issuer outstanding. As of December 31, 2025, Joel Greenblatt may have been deemed to have beneficially owned approximately 1.0% of the shares of Common Stock of the Issuer outstanding. Such percentages are based on 143,955,400 shares of Common Stock outstanding as of October 28, 2025, as disclosed in the Issuer's Form 10-Q filed with the Securities and Exchange Commission on November 4, 2025.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
As of December 31, 2025, Ash X and RLG GP each may have been deemed to have had sole power to vote or to direct the vote of 7,557,202 shares of Common Stock of the Issuer. As of December 31, 2025, RLG Capco II may have been deemed to have had sole power to vote or to direct the vote of 4,733,575 shares of Common Stock of the Issuer. As of December 31, 2025, the Adviser, Gotham Parent and GP of Gotham Parent may have been deemed to have had sole power to vote or to direct the vote of 1,195 shares of Common Stock of the Issuer. As of December 31, 2025, Robert Goldstein may have been deemed to have had sole power to vote or to direct the vote of 12,290,777 shares of Common Stock of the Issuer. As of December 31, 2025, Joel Greenblatt may have been deemed to have had sole power to vote or to direct the vote of 1,428,571 shares of Common Stock of the Issuer.
(ii) Shared power to vote or to direct the vote:
As of December 31, 2025, each of Robert Goldstein and Joel Greenblatt may have been deemed to have had shared power to vote or to direct the vote of 1,195 shares of Common Stock of the Issuer. As of December 31, 2025, each of the Reporting Persons other than Robert Goldstein and Joel Greenblatt may have been deemed to have had shared power to vote or to direct the vote of 0 shares of Common Stock of the Issuer.
(iii) Sole power to dispose or to direct the disposition of:
As of December 31, 2025, Ash X and RLG GP may each have been deemed to have had sole power to dispose or to direct the disposition of 7,557,202 shares of Common Stock of the Issuer. As December 31, 2025, RLG Capco II may have been deemed to have had sole power to dispose or to direct the disposition of 4,733,575 shares of Common Stock of the Issuer. As of December 31, 2025, the Adviser, Gotham Parent and GP of Gotham Parent may have been deemed to have had sole power to dispose or to direct the disposition of 1,195 shares of Common Stock of the Issuer. As of December 31, 2025, Robert Goldstein may have been deemed to have had sole power to dispose or to direct the disposition of 12,290,777 shares of Common Stock of the Issuer. As of December 31, 2025, Joel Greenblatt may have been deemed to have had sole power to dispose or to direct the disposition of 1,428,571 shares of Common Stock of the Issuer.
(iv) Shared power to dispose or to direct the disposition of:
As of December 31, 2025, each of Robert Goldstein and Joel Greenblatt may have been deemed to have had shared power to dispose or to direct the disposition of 1,195 shares of Common Stock of the Issuer. As of December 31, 2025, each of the Reporting Persons other than Robert Goldstein and Joel Greenblatt may have been deemed to have had shared power to dispose or to direct the disposition of 0 shares of Common Stock of the Issuer.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
The disclosure regarding the relationship between the Reporting Persons in Item 4 is incorporated by reference herein.
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
Ash X LP
Signature:
/s/ Robert Goldstein
Name/Title:
Robert Goldstein/Managing Member, RLG GP LLC, its General Partner
Date:
02/10/2026
RLG GP LLC
Signature:
/s/ Robert Goldstein
Name/Title:
Robert Goldstein/Managing Member
Date:
02/10/2026
RLG Capco II LLC
Signature:
/s/ Robert Goldstein
Name/Title:
Robert Goldstein/Manager
Date:
02/10/2026
Gotham Asset Management, LLC
Signature:
/s/ Robert Goldstein
Name/Title:
Robert Goldstein/Managing Principal and Co-Chief Investment Officer
What ownership stake in OmniAb (OABI) does Robert Goldstein report?
Robert Goldstein may have been deemed to beneficially own about 8.5% of OmniAb’s common stock, or 12,291,972 shares. This total reflects both his direct holdings and shares attributed through entities he manages or controls as of December 31, 2025.
How many OmniAb (OABI) shares are held by Ash X LP and RLG GP LLC?
Ash X LP was the direct holder and beneficial owner of 7,557,202 OmniAb shares. As general partner of Ash X, RLG GP LLC may have been deemed to beneficially own the same 7,557,202 shares, representing approximately 5.3% of OmniAb’s outstanding common stock.
What is Joel Greenblatt’s reported ownership in OmniAb (OABI)?
Joel Greenblatt may have been deemed to beneficially own approximately 1.0% of OmniAb’s common stock, totaling 1,429,766 shares. This includes his direct holding of 1,428,571 shares and an additional 1,195 shares attributed through a managed account structure.
How large is RLG Capco II LLC’s position in OmniAb (OABI)?
RLG Capco II LLC was the direct holder and beneficial owner of 4,733,575 OmniAb common shares. As of December 31, 2025, this stake represented about 3.3% of the company’s outstanding common stock, based on 143,955,400 shares reported as outstanding.
Is the OmniAb (OABI) stake reported in this Schedule 13G/A passive or activist?
The reporting persons certify the OmniAb securities were acquired and are held in the ordinary course of business, not to change or influence control. They also state the holdings are not in connection with transactions intended to affect control, indicating a passive investment posture.
What share count did the OmniAb (OABI) holders use to calculate their ownership percentages?
Ownership percentages are based on 143,955,400 OmniAb common shares outstanding as of October 28, 2025. That outstanding share figure comes from OmniAb’s Form 10-Q filed with the SEC on November 4, 2025, and underpins all percentage calculations in the ownership disclosure.
