Company · Ownership research

TANDEM DIABETES CARE INC TNDM

CIK 0001438133 · CUSIP 875372203

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 875372203 (TNDM), not CUSIP 875372903 (TNDM), CUSIP 875372953 (TNDM), and does not merge CUSIPs.

This page lists the top 20 of 269 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	BlackRock, Inc. CIK 2012383 · View history	$245.06M 11,149,181 shares	0.00%	-952.29K(-7.90%)Reduced	SEC filing ↗ Feb 12, 2026	▾
02	VANGUARD GROUP INC CIK 102909 · View history	$161.36M 7,341,356 shares	0.00%	+278.04K(+3.90%)Added	SEC filing ↗ Jan 29, 2026	▾
03	Sessa Capital IM, L.P. CIK 1595849 · View history	$109.90M 5,000,000 shares	2.18%	0(0.00%)Unchanged	SEC filing ↗ Feb 17, 2026	▾
04	ArrowMark Colorado Holdings LLC CIK 1483859 · View history	$63.52M 2,889,691 shares	1.40%	-801.51K(-21.70%)Reduced	SEC filing ↗ Feb 17, 2026	▾
05	GW&K Investment Management, LLC CIK 1082917 · View history	$58.80M 2,675,157 shares	0.51%	-46.49K(-1.70%)Reduced	SEC filing ↗ Feb 11, 2026	▾
06	STATE STREET CORP CIK 93751 · View history	$58.07M 2,641,724 shares	0.00%	-26.46K(-1.00%)Reduced	SEC filing ↗ Feb 13, 2026	▾
07	CITADEL ADVISORS LLC CIK 1423053 · View history	$45.91M 2,088,603 shares	0.03%	+2.05M(+5,147.60%)Added	SEC filing ↗ Feb 17, 2026	▾
08	MORGAN STANLEY CIK 895421 · Amended · View history	$45.73M 2,080,497 shares	0.00%	+1.34M(+182.10%)Added	SEC filing ↗ May 27, 2026	▾
09	Paradice Investment Management LLC CIK 1620275 · View history	$45.67M 2,077,745 shares	8.89%	-118.72K(-5.40%)Reduced	SEC filing ↗ Jan 28, 2026	▾
10	JENNISON ASSOCIATES LLC CIK 53417 · View history	$44.43M 2,021,376 shares	0.03%	+601.26K(+42.30%)Added	SEC filing ↗ Jan 30, 2026	▾
11	GOLDMAN SACHS GROUP INC CIK 886982 · Amended · View history	$37.00M 1,683,400 shares	0.01%	+252.03K(+17.60%)Added	SEC filing ↗ Mar 25, 2026	▾
12	JACOBS LEVY EQUITY MANAGEMENT, INC CIK 884414 · View history	$36.35M 1,653,708 shares	0.14%	+171.75K(+11.60%)Added	SEC filing ↗ Feb 13, 2026	▾
13	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$36.26M 1,649,383 shares	0.00%	+51.10K(+3.20%)Added	SEC filing ↗ Feb 9, 2026	▾
14	Driehaus Capital Management LLC CIK 938206 · View history	$35.40M 1,610,342 shares	0.24%	+1.61MNew	SEC filing ↗ Feb 17, 2026	▾
15	Freestone Grove Partners LP CIK 2007591 · View history	$31.71M 1,442,836 shares	0.23%	-427.47K(-22.90%)Reduced	SEC filing ↗ Feb 17, 2026	▾
16	BNP PARIBAS FINANCIAL MARKETS CIK 1166588 · View history	$27.44M 1,248,481 shares	0.02%	+1.03M(+468.50%)Added	SEC filing ↗ Feb 10, 2026	▾
17	Assenagon Asset Management S.A. CIK 1546007 · View history	$26.99M 1,227,856 shares	0.04%	+1.23MNew	SEC filing ↗ Jan 9, 2026	▾
18	TWO SIGMA INVESTMENTS, LP CIK 1179392 · View history	$26.41M 1,201,527 shares	0.04%	+84.33K(+7.50%)Added	SEC filing ↗ Feb 17, 2026	▾
19	BAILLIE GIFFORD & CO CIK 1088875 · View history	$25.18M 1,145,516 shares	0.02%	+24.92K(+2.20%)Added	SEC filing ↗ Jan 23, 2026	▾
20	First Light Asset Management, LLC CIK 1600004 · View history	$23.95M 1,089,493 shares	1.83%	+1.09MNew	SEC filing ↗ Feb 17, 2026	▾

Showing 20 / 269 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

269

Cancelled or null records excluded

Disclosed shares

74,868,823

Not deduplicated across managers

Disclosed value

$1.65B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

TANDEM DIABETES CARE INC · Q4 2025

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.