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 255 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	$146.91M 12,101,471 shares	0.00%	+1.23M(+11.30%)Added	SEC filing ↗ Nov 12, 2025	▾
02	VANGUARD GROUP INC CIK 102909 · View history	$85.75M 7,063,314 shares	0.00%	-306.52K(-4.20%)Reduced	SEC filing ↗ Nov 7, 2025	▾
03	Sessa Capital IM, L.P. CIK 1595849 · View history	$60.70M 5,000,000 shares	1.53%	0(0.00%)Unchanged	SEC filing ↗ Nov 14, 2025	▾
04	ArrowMark Colorado Holdings LLC CIK 1483859 · View history	$44.81M 3,691,198 shares	0.83%	+991.65K(+36.70%)Added	SEC filing ↗ Nov 14, 2025	▾
05	GW&K Investment Management, LLC CIK 1082917 · View history	$33.04M 2,721,649 shares	0.29%	-168.48K(-5.80%)Reduced	SEC filing ↗ Nov 12, 2025	▾
06	STATE STREET CORP CIK 93751 · View history	$32.39M 2,668,188 shares	0.00%	+22.30K(+0.80%)Added	SEC filing ↗ Nov 14, 2025	▾
07	Hood River Capital Management LLC CIK 1578177 · View history	$30.98M 2,551,644 shares	0.37%	-13.33K(-0.50%)Reduced	SEC filing ↗ Nov 14, 2025	▾
08	Paradice Investment Management LLC CIK 1620275 · View history	$26.67M 2,196,468 shares	5.98%	+429.29K(+24.30%)Added	SEC filing ↗ Oct 20, 2025	▾
09	Freestone Grove Partners LP CIK 2007591 · View history	$22.71M 1,870,307 shares	0.17%	+1.87MNew	SEC filing ↗ Nov 14, 2025	▾
10	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$19.41M 1,598,281 shares	0.00%	-8.05K(-0.50%)Reduced	SEC filing ↗ Nov 12, 2025	▾
11	UBS Group AG CIK 1610520 · View history	$18.26M 1,504,377 shares	0.00%	+120.43K(+8.70%)Added	SEC filing ↗ Nov 13, 2025	▾
12	JACOBS LEVY EQUITY MANAGEMENT, INC CIK 884414 · View history	$17.99M 1,481,953 shares	0.07%	+50.65K(+3.50%)Added	SEC filing ↗ Nov 17, 2025	▾
13	GOLDMAN SACHS GROUP INC CIK 886982 · View history	$17.38M 1,431,372 shares	0.00%	-455.10K(-24.10%)Reduced	SEC filing ↗ Nov 14, 2025	▾
14	JENNISON ASSOCIATES LLC CIK 53417 · View history	$17.24M 1,420,116 shares	0.01%	-238.83K(-14.40%)Reduced	SEC filing ↗ Oct 30, 2025	▾
15	BARCLAYS PLC CIK 312069 · Amended · View history	$14.45M 1,190,127 shares	0.01%	+623.05K(+109.90%)Added	SEC filing ↗ Mar 31, 2026	▾
16	BAILLIE GIFFORD & CO CIK 1088875 · View history	$13.60M 1,120,595 shares	0.01%	-5.13K(-0.50%)Reduced	SEC filing ↗ Oct 31, 2025	▾
17	TWO SIGMA INVESTMENTS, LP CIK 1179392 · View history	$13.56M 1,117,202 shares	0.02%	-115.53K(-9.40%)Reduced	SEC filing ↗ Nov 14, 2025	▾
18	TWO SIGMA ADVISERS, LP CIK 1478735 · View history	$11.79M 970,883 shares	0.02%	+82.80K(+9.30%)Added	SEC filing ↗ Nov 14, 2025	▾
19	ACADIAN ASSET MANAGEMENT LLC CIK 916542 · View history	$11.14M 918,723 shares	0.02%	+560.21K(+156.30%)Added	SEC filing ↗ Nov 13, 2025	▾
20	D. E. Shaw & Co., Inc. CIK 1009207 · View history	$10.65M 877,217 shares	0.01%	+538.55K(+159.00%)Added	SEC filing ↗ Nov 14, 2025	▾

Showing 20 / 255 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

255

Cancelled or null records excluded

Disclosed shares

75,082,306

Not deduplicated across managers

Disclosed value

$911.35M

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 · Q3 2025

Explore all 255 reporting institutions.

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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.