ArrowMark Colorado Holdings discloses 4.26% TNDM stake in 13G/A filing

Rhea-AI Filing Summary

ArrowMark Colorado Holdings, LLC filed an amended Schedule 13G to report its passive ownership in DIABETES CARE INC common stock. As of the event date of 12/31/2025, ArrowMark reported beneficial ownership of 2,889,691 shares, representing 4.26% of the outstanding common stock.

ArrowMark, a Delaware entity, disclosed sole voting and dispositive power over all of these shares and no shared power with other parties. It certified that the shares were acquired and are held in the ordinary course of business, not for the purpose of changing or influencing control of the company.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

TANDEM DIABETES CARE INC

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

875372203

(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. 875372203

1

Names of Reporting Persons

ArrowMark Colorado 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,889,691.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,889,691.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,889,691.00

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)

4.26 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: TANDEM DIABETES CARE INC
(b)	Address of issuer's principal executive offices: 12400 HIGH BLUFF DRIVE, San Diego, CA, 92130
Item 2.
(a)	Name of person filing: ArrowMark Colorado Holdings, LLC
(b)	Address or principal business office or, if none, residence: 100 Fillmore Street, Suite 325, Denver, Colorado 80206
(c)	Citizenship: Delaware, United States
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 875372203
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: 2,889,691
(b)	Percent of class: 4.26%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 2,889,691
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 2,889,691
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
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:

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.

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.

ArrowMark Colorado Holdings, LLC

Signature:	Richard Grove
Name/Title:	Richard Grove | Chief Compliance Officer
Date:	02/17/2026

FAQ

What does ArrowMark’s Schedule 13G/A filing for TNDM report?

The filing reports that ArrowMark Colorado Holdings, LLC beneficially owns 2,889,691 shares of DIABETES CARE INC common stock, equal to 4.26% of the class as of December 31, 2025, and holds these shares on a passive, non‑control basis.

How large is ArrowMark’s ownership stake in TNDM?

ArrowMark reported beneficial ownership of 2,889,691 shares of DIABETES CARE INC common stock, representing 4.26% of the outstanding class as of December 31, 2025. This places its stake below the 5% threshold typically associated with larger reporting shareholders.

Does ArrowMark have voting control over its TNDM shares?

Yes. ArrowMark disclosed sole voting power over all 2,889,691 DIABETES CARE INC shares it beneficially owns. It reported zero shared voting power, meaning decisions on voting these shares rest solely with ArrowMark rather than with any other party.

Is ArrowMark’s TNDM position intended to influence control of the company?

No. ArrowMark certified the DIABETES CARE INC shares were acquired and are held in the ordinary course of business, not to change or influence control of the issuer, and not in connection with any transaction designed to have that effect, consistent with passive ownership reporting.

Why is this TNDM filing labeled as Schedule 13G/A Amendment No. 1?

The designation Schedule 13G/A Amendment No. 1 indicates ArrowMark is updating a previously filed beneficial ownership report. This amendment refreshes its disclosed holdings, showing a 4.26% stake in DIABETES CARE INC common stock as of December 31, 2025.

Who signed the Schedule 13G/A filed for TNDM on behalf of ArrowMark?

The filing was signed by Richard Grove, Chief Compliance Officer of ArrowMark Colorado Holdings, LLC. By signing, he certified that the information regarding DIABETES CARE INC share ownership is true, complete, and correct to the best of his knowledge and belief.