Company Analysis

Tandem Diabetes Care, Inc. (TNDM)

Nasdaq: TNDM · Surgical & Medical Instruments & Apparatus · San Diego, CA · filing with the SEC since 2008
Grade5.0
◀ Past 5.8● Present 5.3▶ Future 3.7
1 est.

Who owns Tandem Diabetes Care, Inc.

As filed with the SEC
Holders of 5% or more
4
Blackrock, Inc. holds 15.2% of Common Stock, as its SCHEDULE 13G/A filed Apr 29, 2025 says.
Directors and officers
17
report now, of 29 people on the record since 2013. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 4 named at left.
Holders of 5% or moreshare of the class, as filed
Blackrock, Inc.
15.2%
Sessa Capital (Master), L.P.
SCHEDULE 13G · filed May 15, 2025 · Common Stock, par value $0.001 per share
6.71%
Vanguard Portfolio Management
5.91%
Vanguard Capital Management
5.18%
ArrowMark Colorado Holdings, LLC
SCHEDULE 13G/A · filed Feb 17, 2026 · Common Stock, par value $0.001 per share · reported falling below 5%, from 5.46% in Nov 13, 2025
under 5%
Voya Financial, Inc.
SCHEDULE 13G/A · filed Aug 6, 2026 · Common Stock, par value $0.001 per share · reported falling below 5%, from 6.3% in May 5, 2026
under 5%
The Vanguard Group
SCHEDULE 13G/A · filed Mar 27, 2026 · Common Stock · reported falling below 5%
under 5%
What TNDM reports owning in othersstakes of 5% or more, and other ties
Other ties the annual report names
AMF Medical Acquisition
A company bought · asset acquisition · owns, named in the 10-K filed Feb 19, 2026

9 subsidiaries in 7 countries, from the list filed with the 10-K filed Feb 19, 2026.

Insider tradesForm 4
3sales
0purchases
2sales on a scheduled plan
2people selling
$0sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Oct 29, 2025 to Oct 29, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
17181920212223242526
2026 runs to Oct 29, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window2 of 29 on the roster
PersonRole as filedSalesSoldOn a planBuysBought
Novara Mark DavidEVP & CHIEF COMMERCIAL OFFICER2$010$0
Twomey Christopher Jdirector1$010$0
SI Assistanton TNDM · research, not advice