TNDM

Tandem Diabetes Care Inc
Health CareUSCUSIP 875372203◍ Confluence graph
Tracked 13F Holders
247
-127 QoQ
13F Value (tracked)
$1.3B
Insider Net · 180d
-$4K
0↑ 1↓
Recent Filings
15
Smart-money sentimentMixed
BearishBullish
13F funds (latest Q)41 adding · 19 trimming
Insider net (180d)-$4K

Who owns TNDM?

247 tracked 13F filers

247 tracked 13F filers disclose a position in TNDM as of the latest SEC 13F filings, a combined $1.3B in reported value. Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

All quarters use one ordinary-share-equivalent series. Historical ADS are converted at 2 ADS = 1 ordinary share. Expand a row for the exact calculation; the residual is not classified as a trade.
1 source-reported value row is withheld because the reported units do not agree with same-security peers. Share counts remain visible and unchanged.
#FundPosition valueSharesLast moveAs ofHistory
1BlackRock, Inc.
$204.9M
10.7M
−4.1%
Reduced · −458K sh
Q1 2026
2Sessa Capital IM, L.P.
$90.7M
4.7M
−5.4%
Reduced · −269K sh
Q1 2026
3VANGUARD PORTFOLIO MANAGEMENT LLC
$76.6M
4.0M
First observed position
No prior filed position
Q1 2026
4ArrowMark Colorado Holdings LLC
$59.5M
3.1M
+7.4%
Added · +214K sh
Q1 2026
5VANGUARD CAPITAL MANAGEMENT LLC
$58.3M
3.0M
First observed position
No prior filed position
Q1 2026
6STATE STREET CORP
$43.0M
2.9M
+7.1%
Added · +189K sh
Q2 2026
7GOLDMAN SACHS GROUP INC
$42.5M
2.2M
+32%
Added · +536K sh
Q1 2026
8CITADEL ADVISORS LLC
$42.0M
2.2M
+5.0%
Added · +104K sh
Q1 2026
9UBS Group AG
$39.3M
2.0M
+390%
Added · +1.6M sh
Q1 2026
10Paradice Investment Management LLC
$30.5M
2.0M
−0.9%
Reduced · −18K sh
Q2 2026
11TWO SIGMA INVESTMENTS, LP
$35.7M
1.9M
+55%
Added · +663K sh
Q1 2026
12GEODE CAPITAL MANAGEMENT, LLC
$27.2M
1.8M
+7.2%
Added · +121K sh
Q2 2026
13JENNISON ASSOCIATES LLC
$31.8M
1.7M
−18%
Reduced · −363K sh
Q1 2026
14JACOBS LEVY EQUITY MANAGEMENT, INC
$29.2M
1.5M
−7.8%
Reduced · −130K sh
Q1 2026
15MARSHALL WACE, LLP
$27.7M
1.4M
+65%
Added · +567K sh
Q1 2026
16MORGAN STANLEY
$26.0M
1.4M
−35%
Reduced · −723K sh
Q1 2026
17Freestone Grove Partners LP
$25.5M
1.3M
−7.8%
Reduced · −112K sh
Q1 2026
18First Light Asset Management, LLC
$25.2M
1.3M
+21%
Added · +225K sh
Q1 2026
19BAILLIE GIFFORD & CO
$20.9M
1.1M
−4.9%
Reduced · −56K sh
Q1 2026
20VOYA INVESTMENT MANAGEMENT LLC
$15.4M
804K
+152%
Added · +485K sh
Q1 2026
21D. E. Shaw & Co., Inc.
$15.0M
784K
−8.2%
Reduced · −70K sh
Q1 2026
22Defilade Capital Management, L.P.
$14.6M
762K
New
+762K sh
Q1 2026
23MILLENNIUM MANAGEMENT LLC
$14.6M
762K
+31%
Added · +178K sh
Q1 2026
24FMR LLC
$13.7M
714K
+6.1%
Added · +41K sh
Q1 2026
25NORTHERN TRUST CORP
$13.5M
707K
+2.1%
Added · +15K sh
Q1 2026

Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

Is TNDM being bought or sold by institutions?

Last quarter, 11 funds opened a new position in TNDM and 30 added to an existing one, while 19 reduced and 0 exited entirely — based on 13F filings from active, signal-eligible managers (passive index funds and other mechanical holders are excluded from this count).

Opened (NEW)
11
funds
Added
30
funds
Reduced
19
funds
Exited
0
funds

Funds that own TNDM also own

CompanyCo-held byCombined value
AMAZON.COM INCAMZN132 funds$177.3B
META PLATFORMS INC-CLASS AMETA132 funds$95.0B
NVIDIA CORPNVDA130 funds$335.5B
MICROSOFT CORPMSFT129 funds$225.0B
ELI LILLY & COLLY129 funds$67.8B
APPLE INCAAPL127 funds$246.3B
JPMORGAN CHASE & COJPM126 funds$47.9B
CHEVRON CORPCVX126 funds$25.0B
UNITEDHEALTH GROUP INCUNH126 funds$23.9B
COSTCO WHOLESALE CORPCOST125 funds$32.9B
MICRON TECHNOLOGY INCMU125 funds$32.5B
BANK OF AMERICA CORPBAC125 funds$26.0B

Ranked by how many of TNDM's institutional holders also hold each name, a cross-fund conviction signal.

Insider activity (Form 4)

Full insider page →
Buys · 180d
$0
0 insiders
Sells · 180d
$4K
1 insiders
Net
-$4K
1 P/S txns
Signal
Net Selling
open-market
DateInsiderRoleActionSharesValue
Mar 17, 2026Novara Mark DavidEVP & CHIEF COMMERCIAL OFFICERSell (S)187$4K
Mar 5, 2026Novara Mark DavidEVP & CHIEF COMMERCIAL OFFICERSell (S)2$46
Aug 11, 2025Sheridan John FPRESIDENT & CEO, DirectorBuy (P)10K$102K
Aug 8, 2025Vosseller LeighEVP & CHIEF FINANCIAL OFFICERBuy (P)14K$149K
Mar 7, 2025Kyrillos Jean-ClaudeEVP & Chief Operating OfficerBuy (P)11K$191K
Nov 21, 2024BLICKENSTAFF KIM DDirectorSell (S)30K$941K
Nov 20, 2024BLICKENSTAFF KIM DDirectorSell (S)10K$300K
Nov 15, 2024Novara Mark DavidEVP & CHIEF COMMERCIAL OFFICERBuy (P)532$12K
May 30, 2024Allen DickDirectorSell (S)5K$258K
Nov 27, 2023Allen DickDirectorBuy (P)5K$95K
Nov 8, 2023Hansen Shannon MarieChief Legal OfficerBuy (P)2K$30K
Nov 8, 2023Vosseller LeighEVP & CHIEF FINANCIAL OFFICERBuy (P)6K$95K

Institutional ownership over time

109 funds-136 since Q3 2024
0123245Q3 2024Q1 2025Q3 2025Q1 2026Q2 2026
funds holding aggregate valuelatest $195.1M

Share classes

Class13F holdersValue held
TNDMthis pagecs247 funds$1.3B
TNDM 1.5 03/15/29 2024SDBCV22 funds$332.0M

Same issuer, multiple share classes. The consensus leaderboards count this company once across all classes; this is the per-class detail.

Recent filings

15 shown

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Connected entities for TNDM

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Ask your agent what changed in TNDM

This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/stocks/TNDM/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for TNDM.
Tell me what changed, whether insider activity
corroborates it, and cite the SEC evidence.

13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for TNDM. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.