TNDMTandem Diabetes Care, Inc.

$21.35

Who owns TNDM

271 institutions reported holding TNDM for 2026Q1, together 115% of the company, more than the 266 a quarter earlier.

271

Institutions reporting a position · as of 2026Q1 · up from 266 the quarter before

Shares held by institutions
78.7M

Shares held by institutions · 115% of the company · long US equity positions only, as reported on Form 13F

Reported value
$1.51B

Reported value · at 2026-03-31 prices, not today's

Opened vs closed
40 / 40

Opened vs closed · new positions against positions exited in the latest quarter

Details
Reporting quarter2026-03-31
2026Q1
Quarters on record
50
New positions
40
Positions exited
40
Added to
93
Reduced
88
Institutional ownership by quarter, 2013Q4 to 2026Q1
QuarterFilersSharesReported value
2026Q127178.7M$1.51B
2025Q426674.9M$1.65B
2025Q325274.8M$908M
2025Q226680.7M$1.50B
2025Q127273.0M$1.40B
2024Q431472.0M$2.59B
2024Q332772.8M$3.09B
2024Q231273.0M$2.94B
2024Q128873.8M$2.61B
2023Q426670.9M$2.10B
2023Q322469.6M$1.44B
2023Q224567.2M$1.65B
2023Q127168.0M$2.76B
2022Q429464.3M$2.89B
2022Q329762.6M$3.00B
2022Q232561.2M$3.62B
Largest reported holders, 2026Q1
HolderShares% of companyValue
BlackRock Inc.10.7Mn/a$205M
VANGUARD GROUP INC7.6Mn/a$146M
Sessa Capital IM, L.P.4.7Mn/a$91M
ArrowMark Colorado Holdings LLC3.1Mn/a$59M
GW&K Investment Management, LLC2.7Mn/a$52M
STATE STREET CORP2.7Mn/a$51M
Driehaus Capital Management LLC2.3Mn/a$44M
GOLDMAN SACHS GROUP INC2.2Mn/a$43M
CITADEL ADVISORS LLC2.2Mn/a$42M
UBS Group AG2.0Mn/a$39M

SEC Form 13F data sets (DERA bulk files). 13F is quarterly, filed up to 45 days late, and covers long US equity positions only, no shorts, no derivatives, nothing held below the reporting threshold.

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