C3.ai reports Amendment No. 6 to its Schedule 13G/A reflecting Thomas M. Siebel's beneficial ownership as of March 31, 2026. The filing lists 3,072,820 shares of Class B Common Stock and 22,483,831 shares of Class A Common Stock attributable to Mr. Siebel and related entities, and states Mr. Siebel beneficially owned 15.3% of outstanding Class A Common Stock. The filing discloses 25,556,651 shares as the number over which Mr. Siebel has sole voting power and notes a reported decrease in his Class A ownership of approximately 1.3% compared to the prior Amendment No. 5.
Positive
None.
Negative
None.
Insights
Siebel continues to hold significant voting control via Class B and related entities.
The filing shows Mr. Siebel and affiliated entities hold both Class B and Class A shares with 25,556,651 shares listed under sole voting power as of March 31, 2026. The Class B shares convert 1-for-1 to Class A and carry 50 votes per share, which preserves concentrated voting influence.
Reported changes include a ~1.3% decrease in Class A beneficial ownership versus the prior amendment. Subsequent disclosures or transactions will determine whether this trend continues; timing and cash‑flow treatment are not specified in the provided excerpt.
Key Figures
Class A shares attributable:22,483,831 sharesClass B shares attributable:3,072,820 sharesSole voting power:25,556,651 shares+4 more
7 metrics
Class A shares attributable22,483,831 sharesas of <date>March 31, 2026</date>
Class B shares attributable3,072,820 sharesas of <date>March 31, 2026</date>
Sole voting power25,556,651 sharessole voting power reported
Reported Class A ownership percent15.3%percent of outstanding Class A as of <date>March 31, 2026</date>
Options exercisable within 60 days20,237,982 sharescould be issued upon exercise within 60 days of <date>March 31, 2026</date>
RSUs vesting within 60 days53,125 sharescould be issued upon RSU vesting within 60 days of <date>March 31, 2026</date>
Reported ownership change1.3%decrease versus Amendment No. 5 (Nov 14, 2025)
Key Terms
beneficially owned, irrevocable proxy, convertible at the holder's option, restricted stock units, +1 more
5 terms
beneficially ownedregulatory
"As of March 31, 2026: 3,072,820 shares of the Issuer's Class B Common Stock and 22,483,831 shares of the Issuer's Class A Common Stock"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
irrevocable proxyregulatory
"500,000 shares of Class B Common Stock and 9,216 shares of Class A Common Stock over which Mr. Siebel holds an irrevocable proxy"
An irrevocable proxy is a legal authorization in which a shareholder gives another person or entity the permanent right to vote their shares and cannot later take that voting permission back. It matters to investors because it locks who controls voting power on key issues—like board elections, mergers, or major policy changes—so it can change corporate control and influence the value or direction of an investment much like handing someone an unchangeable voting card.
convertible at the holder's optionfinancial
"The Class B Common Stock is convertible at the holder's option into the Issuer's Class A Common Stock on a 1-for-1 basis"
restricted stock unitsfinancial
"53,125 shares of Class A Common Stock that could be issued to Mr. Siebel in connection with the vesting of restricted stock units"
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
sole dispositive powerregulatory
"Sole Dispositive Power 25,556,651.00"
Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 6)
C3.ai, Inc.
(Name of Issuer)
Class A Common Stock, $0.001 par value per share
(Title of Class of Securities)
12468P104
(CUSIP Number)
03/31/2026
(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)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
Thomas M Siebel
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
25,556,651.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
25,556,651.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
25,556,651.00
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)
15.3 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
The Siebel Living Trust u/a/d 7/27/93, as amended
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
CALIFORNIA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
2,767,008.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
2,767,008.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,767,008.00
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)
1.9 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
Siebel Asset Management, L.P.
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
CALIFORNIA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
170,294.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
170,294.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
170,294.00
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)
0.1 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
Siebel Asset Management III, L.P.
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
CALIFORNIA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
72,695.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
72,695.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
72,695.00
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)
0.1 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
First Virtual Holdings, 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
CALIFORNIA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
509,216.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
509,216.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
509,216.00
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)
0.4 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
12468P104
1
Names of Reporting Persons
The Siebel 2011 Irrevocable Children's Trust
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
CALIFORNIA
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
1,237,115.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
1,237,115.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,237,115.00
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)
0.9 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
C3.ai, Inc.
(b)
Address of issuer's principal executive offices:
1400 Seaport Blvd., Redwood City, CA, 94063.
Item 2.
(a)
Name of person filing:
Thomas M. Siebel ("Thomas M. Siebel")
Siebel Living Trust 1993 Revocable Trust ("Living Trust")
Siebel Asset Management, L.P. ("SAM")
Siebel Asset Management III, L.P. ("SAM III")
First Virtual Holdings, LLC ("First Virtual")
The Siebel 2011 Irrevocable Children's Trust ("Children's Trust")
(b)
Address or principal business office or, if none, residence:
c/o C3.ai, Inc.
1400 Seaport Blvd
Redwood City, CA 94063
(c)
Citizenship:
Thomas M. Siebel is a citizen of the United States. The other filers are each organized under the laws of the State of California.
(d)
Title of class of securities:
Class A Common Stock, $0.001 par value per share
(e)
CUSIP No.:
12468P104
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 March 31, 2026: 3,072,820 shares of the Issuer's Class B Common Stock and 22,483,831 shares of the Issuer's Class A Common Stock, of which (a) 2,072,820 shares of Class B Common Stock and 694,188 shares of Class A Common Stock were held by Living Trust, for which Mr. Siebel serves as trustee, (b) 170,294 shares of Class A Common Stock were held by SAM, for which Mr. Siebel serves as the general partner, (c) 72,695 shares of Class A Common Stock were held by SAM III, for which Mr. Siebel serves as the general partner, (d) 500,000 shares of Class B Common Stock and 9,216 shares of Class A Common Stock were held by First Virtual, for which Mr. Siebel serves as Chairman, (e) 1,237,115 shares of Class A Common Stock were held by Children's Trust, of which Mr. Siebel is trustee, (f) 500,000 shares of Class B Common Stock and 9,216 shares of Class A Common Stock over which Mr. Siebel holds an irrevocable proxy pursuant to a voting agreement between Mr. Siebel and Patricia A. House, (g) 20,237,982 shares of Class A Common Stock that could be issued to Mr. Siebel in connection with the exercise of stock options within 60 days of March 31, 2026 and (h) 53,125 shares of Class A Common Stock that could be issued to Mr. Siebel in connection with the vesting of restricted stock units within 60 days of March 31, 2026. The Class B Common Stock is convertible at the holder's option into the Issuer's Class A Common Stock on a 1-for-1 basis. The holders of Class B Common Stock are entitled to 50 votes per share and the holders of Class A Common Stock are entitled to one vote per share.
(b)
Percent of class:
As of March 31, 2026:
(A) Thomas M. Siebel beneficially owned 15.3% of the Issuer's outstanding Class A Common Stock;
(B) Living Trust beneficially owned 1.9% of the Issuer's outstanding Class A Common Stock;
(C) SAM beneficially owned 0.1% of the Issuer's outstanding Class A Common Stock;
(D) SAM III beneficially owned 0.1% of the Issuer's outstanding Class A Common Stock;
(E) First Virtual beneficially owned 0.4% of the Issuer's outstanding Class A Common Stock;
and (F) Children's Trust beneficially owned 0.9% of the Issuer's outstanding Class A Common Stock.
This Amendment No. 6 to Schedule 13G is being filed to report a decrease in Thomas M. Siebel's beneficial ownership of the Issuer's Class A Common Stock (compared to the ownership information last reported on that certain Amendment No. 5 to Schedule 13G filed November 14, 2025) of approximately 1.3%.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
Thomas M. Siebel: 25,556,651
Living Trust: 2,767,008
SAM: 170,294
SAM III: 72,695
First Virtual: 509,216
Children's Trust: 1,237,115
(ii) Shared power to vote or to direct the vote:
Thomas M. Siebel: 0
Living Trust: 0
SAM: 0
SAM III: 0
First Virtual: 0
Children's Trust: 0
(iii) Sole power to dispose or to direct the disposition of:
Thomas M. Siebel: 25,556,651
Living Trust: 2,767,008
SAM: 170,294
SAM III: 72,695
First Virtual: 509,216
Children's Trust: 1,237,115
(iv) Shared power to dispose or to direct the disposition of:
Thomas M. Siebel: 0
Living Trust: 0
SAM: 0
SAM III: 0
First Virtual: 0
Children's Trust: 0
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.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
Not Applicable
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.
Thomas M Siebel
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel
Date:
05/15/2026
The Siebel Living Trust u/a/d 7/27/93, as amended
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel, Trustee of The Siebel Living Trust u/a/d 7/27/93, as amended
Date:
05/15/2026
Siebel Asset Management, L.P.
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel, General Partner
Date:
05/15/2026
Siebel Asset Management III, L.P.
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel, General Partner
Date:
05/15/2026
First Virtual Holdings, LLC
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel, Chairman
Date:
05/15/2026
The Siebel 2011 Irrevocable Children's Trust
Signature:
/s/ Thomas M. Siebel
Name/Title:
Thomas M. Siebel, Trustee of The Siebel 2011 Irrevocable Children's Trust
How many Class A shares does Thomas M. Siebel beneficially own in C3.ai (AI)?
Mr. Siebel is attributed with 22,483,831 shares of Class A Common Stock as of March 31, 2026. This total combines direct holdings, shares held by trusts and entities, and shares issuable upon exercise of options and RSU vesting within 60 days.
What Class B holdings does the filing report for Thomas M. Siebel (AI)?
The filing reports 3,072,820 shares of Class B Common Stock attributable to Mr. Siebel as of March 31, 2026. Class B shares are convertible 1-for-1 into Class A Common Stock and carry 50 votes per share.
How much voting power does Thomas M. Siebel control at C3.ai (AI)?
The filing shows Mr. Siebel has sole voting power over 25,556,651 shares as of March 31, 2026. This figure reflects his direct and affiliated holdings including Class B shares with enhanced voting rights.
Does the filing disclose any shares issuable to Siebel soon (AI)?
Yes. The filing lists 20,237,982 shares that could be issued upon exercise of stock options and 53,125 shares issuable upon RSU vesting within 60 days of March 31, 2026. These figures are included in the beneficial ownership calculation.
Did Thomas M. Siebel's ownership change versus the prior amendment (AI)?
The amendment states Mr. Siebel's beneficial ownership of Class A Common Stock decreased by approximately 1.3% compared to Amendment No. 5 filed November 14, 2025. The filing does not provide transaction-level details explaining the decrease.
