Diabetes Care (TNDM) CFO trust buys 13,720 company shares

Rhea-AI Filing Summary

Diabetes Care Inc EVP & Chief Financial Officer Leigh Vosseller reported an open-market purchase of common stock on August 8, 2025. A trust bearing her name bought 13,720 shares at a weighted average price of $10.8895 per share, through multiple trades between $10.86 and $10.90.

After this transaction, the trust holds 25,580 shares indirectly, while Vosseller also holds 33,798 shares directly. The filing notes that the securities are held by the Leigh A. Vosseller Trust, for which she serves as trustee.

Insider Trade Summary

Net Buyer: 13,720 shares ($149,404)

Net Buy 2 txns

Insider Vosseller Leigh

Role EVP & CHIEF FINANCIAL OFFICER

Bought 13,720 shs ($149K)

Type	Security	Shares	Price	Value
Purchase	Common Stock	13,720	$10.8895	$149K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 25,580 shares (Indirect, Leigh A. Vosseller Trust); Common Stock — 33,798 shares (Direct)

Footnotes (1)

1. This transaction was executed in multiple trades at prices ranging from $10.86 to $10.90 per share. The reported price reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. The securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, of which Leigh Vosseller is the Trustee.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED 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^*

Vosseller Leigh

(Last) (First) (Middle)

12400 HIGH BLUFF DRIVE

(Street)

SAN DIEGO CA 92130

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
TANDEM DIABETES CARE INC [ TNDM ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP & CHIEF FINANCIAL OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
08/08/2025

4. 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 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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/08/2025		P		13,720	A	$10.8895(1)	25,580	I	Leigh A. Vosseller Trust(2)
Common Stock								33,798	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This transaction was executed in multiple trades at prices ranging from $10.86 to $10.90 per share. The reported price reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

2. The securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, of which Leigh Vosseller is the Trustee.

Remarks:

	/s/ Rachel Malina, Attorney-in-Fact for Leigh A. Vosseller	08/11/2025
	** 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 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.

FAQ

What insider transaction did Diabetes Care (TNDM) disclose for Leigh Vosseller?

Diabetes Care disclosed that EVP & CFO Leigh Vosseller’s trust bought 13,720 common shares. The open-market purchase occurred on August 8, 2025, at a weighted average price of $10.8895 per share, executed in multiple trades between $10.86 and $10.90.

At what price did the Diabetes Care (TNDM) CFO’s trust buy shares?

The trust purchased shares at a weighted average price of $10.8895 per share. The Form 4 explains that the trades were executed in multiple lots, with prices ranging from $10.86 to $10.90, and the reported figure represents the averaged purchase price.

How many Diabetes Care (TNDM) shares does the Leigh A. Vosseller Trust hold after the transaction?

After the reported trade, the Leigh A. Vosseller Trust holds 25,580 Diabetes Care shares indirectly. These shares are attributed to EVP & CFO Leigh Vosseller, who serves as trustee of the trust established on January 17, 2010.

What is Leigh Vosseller’s direct share ownership in Diabetes Care (TNDM)?

Leigh Vosseller directly owns 33,798 shares of Diabetes Care common stock. This direct holding is reported separately from the 25,580 shares held indirectly through the Leigh A. Vosseller Trust, providing a clearer picture of her total reported beneficial ownership.

How is the insider ownership structured for Diabetes Care (TNDM) CFO Leigh Vosseller?

Her ownership is split between direct and indirect holdings. The Form 4 shows 33,798 shares held directly and 25,580 shares held indirectly by the Leigh A. Vosseller Trust, where she is trustee, reflecting both personal and trust-based positions in the company.

What role does the Leigh A. Vosseller Trust play in the Diabetes Care (TNDM) Form 4?

The trust is the entity that executed the 13,720-share open-market purchase. The filing clarifies that the securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, with Leigh Vosseller acting as trustee, resulting in indirect beneficial ownership.