TNDM US Equity

TANDEM DIABETES CARE INC

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Health Care · Surgical & Medical Instruments & Apparatus · CIK 1438133 · FYE 1231

$18.59

+0.83 (+4.67%)

USD · as of 2026-07-29 · marketstack

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Institutional ownership· 13F filers holding TNDM · 2026-Q1 methodology → sources →

272 holders

% of shares outstanding held

114.8%

Shares held (13F)

78,656,621

Reporting holders

272

Institutional 13F holdings sum to 114.8% of shares outstanding. Readings above 100% reflect securities-lending double counting: shares on loan to short sellers are reported long by both the lending institution and the one that bought them. FINRA short interest of 9,723,853 shares (settlement 2026-04-30) accounts for the excess.

Top holders

largest 100 of 272 · Δ vs 2025-Q4

#	Holder	Shares	Value	% of shares out	Δ QoQ
1	BlackRock, Inc.	10,690,84410.7M	$205M	15.60%	TRIM -4%
2	Sessa Capital IM, L.P.	4,730,7574.7M	$91M	6.90%	TRIM -5%
3	VANGUARD PORTFOLIO MANAGEMENT LLC	3,993,3334.0M	$77M	5.83%	NEW†
4	ArrowMark Colorado Holdings LLC	3,103,6093.1M	$59M	4.53%	ADD 7%
5	VANGUARD CAPITAL MANAGEMENT LLC	3,038,9193.0M	$58M	4.43%	NEW†
6	GW&K Investment Management, LLC	2,689,1062.7M	$52M	3.92%	—
7	STATE STREET CORP	2,662,2602.7M	$51M	3.88%	—
8	Driehaus Capital Management LLC	2,304,4142.3M	$44M	3.36%	ADD 43%
9	GOLDMAN SACHS GROUP INC	2,218,9222.2M	$43M	3.24%	ADD 32%
10	CITADEL ADVISORS LLC	2,192,6672.2M	$42M	3.20%	ADD 5%
11	UBS Group AG	2,047,8012.0M	$39M	2.99%	ADD 390%
12	Paradice Investment Management LLC	2,042,4252.0M	$39M	2.98%	—
13	TWO SIGMA INVESTMENTS, LP	1,864,1941.9M	$36M	2.72%	ADD 55%
14	GEODE CAPITAL MANAGEMENT, LLC	1,679,8631.7M	$32M	2.45%	—
15	JENNISON ASSOCIATES LLC	1,658,4481.7M	$32M	2.42%	TRIM -18%
16	JACOBS LEVY EQUITY MANAGEMENT, INC	1,523,9461.5M	$29M	2.22%	TRIM -8%
17	MARSHALL WACE, LLP	1,442,4721.4M	$28M	2.10%	ADD 65%
18	MORGAN STANLEY	1,357,5421.4M	$26M	1.98%	TRIM -35%
19	Freestone Grove Partners LP	1,330,7421.3M	$26M	1.94%	TRIM -8%
20	First Light Asset Management, LLC	1,314,7151.3M	$25M	1.92%	ADD 21%
21	BAILLIE GIFFORD & CO	1,089,3931.1M	$21M	1.59%	TRIM -5%
22	WELLINGTON MANAGEMENT GROUP LLP	1,042,7641.0M	$20M	1.52%	ADD 961%
23	VOYA INVESTMENT MANAGEMENT LLC	804,137804,137	$15M	1.17%	ADD 152%
24	D. E. Shaw & Co., Inc.	783,906783,906	$15M	1.14%	TRIM -8%
25	Soleus Capital Management, L.P.	783,000783,000	$15M	1.14%	NEW
26	Defilade Capital Management, L.P.	761,905761,905	$15M	1.11%	NEW
27	MILLENNIUM MANAGEMENT LLC	761,672761,672	$15M	1.11%	ADD 31%
28	FMR LLC	714,011714,011	$14M	1.04%	ADD 6%
29	NORTHERN TRUST CORP	706,609706,609	$14M	1.03%	ADD 2%
30	ROYCE & ASSOCIATES LP	696,590696,590	$13M	1.02%	ADD 7%
31	Quantinno Capital Management LP	653,870653,870	$13M	0.95%	ADD 124%
32	CHARLES SCHWAB INVESTMENT MANAGEMENT INC	642,598642,598	$12M	0.94%	—
33	ExodusPoint Capital Management, LP	632,899632,899	$12M	0.92%	NEW
34	Holocene Advisors, LP	477,359477,359	$9M	0.70%	ADD 2808%
35	VANGUARD FIDUCIARY TRUST CO	471,658471,658	$9M	0.69%	NEW
36	Aberdeen Group plc	434,027434,027	$8M	0.63%	TRIM -21%
37	BARCLAYS PLC	421,236421,236	$8M	0.61%	TRIM -54%
38	Point72 Asset Management, L.P.	420,478420,478	$8M	0.61%	NEW
39	FRONTIER CAPITAL MANAGEMENT CO LLC	397,209397,209	$8M	0.58%	TRIM -4%
40	BANK OF AMERICA CORP /DE/	373,224373,224	$7M	0.54%	TRIM -47%
41	Nuveen, LLC	363,802363,802	$7M	0.53%	TRIM -35%
42	JPMORGAN CHASE & CO	349,792349,792	$7M	0.51%	ADD 2%
43	DAFNA Capital Management LLC	355,208355,208	$7M	0.52%	—
44	FIRST TRUST ADVISORS LP	342,707342,707	$7M	0.50%	NEW
45	Bank of New York Mellon Corp	336,291336,291	$6M	0.49%	TRIM -4%
46	AQR CAPITAL MANAGEMENT LLC	331,916331,916	$6M	0.48%	TRIM -2%
47	PRINCIPAL FINANCIAL GROUP INC	331,541331,541	$6M	0.48%	ADD 2%
48	Invesco Ltd.	294,052294,052	$6M	0.43%	ADD 6%
49	ACADIAN ASSET MANAGEMENT LLC	278,116278,116	$5M	0.41%	TRIM -29%
50	SECTOR GAMMA AS	267,091267,091	$5M	0.39%	—
51	EDMOND DE ROTHSCHILD HOLDING S.A.	258,200258,200	$5M	0.38%	—
52	BEACONLIGHT CAPITAL, LLC	253,877253,877	$5M	0.37%	NEW
53	Trexquant Investment LP	249,298249,298	$5M	0.36%	ADD 143%
54	ENVESTNET ASSET MANAGEMENT INC	243,248243,248	$5M	0.35%	ADD 10%
55	Public Sector Pension Investment Board	242,596242,596	$5M	0.35%	ADD 3%
56	BNP PARIBAS FINANCIAL MARKETS	208,713208,713	$4M	0.30%	TRIM -83%
57	Susquehanna Portfolio Strategies, LLC	206,193206,193	$4M	0.30%	ADD 210%
58	ROYAL BANK OF CANADA	206,033206,033	$4M	0.30%	—
59	ARROWSTREET CAPITAL, LIMITED PARTNERSHIP	193,556193,556	$4M	0.28%	ADD 43%
60	RHUMBLINE ADVISERS	186,316186,316	$4M	0.27%	—
61	Assenagon Asset Management S.A.	178,640178,640	$3M	0.26%	TRIM -85%
62	UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC	168,493168,493	$3M	0.25%	ADD 2%
63	Lisanti Capital Growth, LLC	165,325165,325	$3M	0.24%	TRIM -37%
64	PANAGORA ASSET MANAGEMENT INC	163,695163,695	$3M	0.24%	ADD 12%
65	MIZUHO MARKETS AMERICAS LLC	157,362157,362	$3M	0.23%	ADD 9%
66	Legal & General Group Plc	155,288155,288	$3M	0.23%	TRIM -10%
67	TORONTO DOMINION BANK	150,078150,078	$3M	0.22%	NEW
68	Russell Investments Group, Ltd.	133,596133,596	$3M	0.19%	ADD 4%
69	Swiss National Bank	133,300133,300	$3M	0.19%	—
70	RAYMOND JAMES FINANCIAL INC	125,345125,345	$2M	0.18%	ADD 4%
71	BANQUE PICTET & CIE SA	123,935123,935	$2M	0.18%	ADD 28%
72	FEDERATED HERMES, INC.	123,819123,819	$2M	0.18%	ADD 495176%
73	AMERIPRISE FINANCIAL INC	121,150121,150	$2M	0.18%	TRIM -6%
74	CANADA PENSION PLAN INVESTMENT BOARD	118,439118,439	$2M	0.17%	TRIM -33%
75	ALGERT GLOBAL LLC	117,799117,799	$2M	0.17%	ADD 8%
76	INTECH INVESTMENT MANAGEMENT LLC	111,421111,421	$2M	0.16%	ADD 307%
77	Verition Fund Management LLC	107,119107,119	$2M	0.16%	ADD 912%
78	SEI INVESTMENTS CO	95,30695,306	$2M	0.14%	TRIM -11%
79	Zurcher Kantonalbank (Zurich Cantonalbank)	94,34094,340	$2M	0.14%	ADD 27%
80	PDT Partners, LLC	93,80593,805	$2M	0.14%	TRIM -15%
81	Universal- Beteiligungs- und Servicegesellschaft mbH	87,35787,357	$2M	0.13%	—
82	CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM	84,25584,255	$2M	0.12%	ADD 31%
83	ALLIANCEBERNSTEIN L.P.	73,14973,149	$2M	0.11%	TRIM -69%
84	SUSQUEHANNA INTERNATIONAL GROUP, LLP	80,74980,749	$2M	0.12%	TRIM -38%
85	Nierenberg Investment Management Company, LLC	79,51079,510	$2M	0.12%	ADD 78%
86	TUDOR INVESTMENT CORP ET AL	78,99978,999	$2M	0.12%	TRIM -27%
87	Y-Intercept (Hong Kong) Ltd	77,87977,879	$1M	0.11%	TRIM -7%
88	Cerity Partners LLC	76,22876,228	$1M	0.11%	—
89	RICE HALL JAMES & ASSOCIATES, LLC	72,87872,878	$1M	0.11%	ADD 17%
90	FORMULA GROWTH LTD	70,82870,828	$1M	0.10%	—
91	PRUDENTIAL FINANCIAL INC	69,40469,404	$1M	0.10%	ADD 7%
92	PRICE T ROWE ASSOCIATES INC /MD/	68,66168,661	$1M	0.10%	ADD 21%
93	CITIGROUP INC	68,34668,346	$1M	0.10%	ADD 272%
94	NEW YORK STATE TEACHERS RETIREMENT SYSTEM	66,09666,096	$1M	0.10%	TRIM -3%
95	JONES FINANCIAL COMPANIES LLLP	58,38858,388	$1M	0.09%	ADD 3638%
96	Cinctive Capital Management LP	63,81263,812	$1M	0.09%	NEW
97	NATIXIS ADVISORS, LLC	61,08461,084	$1M	0.09%	ADD 7%
98	XTX Topco Ltd	60,82160,821	$1M	0.09%	NEW
99	DEUTSCHE BANK AG\	60,62960,629	$1M	0.09%	ADD 12%
100	VANGUARD ASSET MANAGEMENT, Ltd	58,28858,288	$1M	0.09%	NEW

† a filer this large appearing as NEW usually reflects a renamed or succeeded filing entity (the old name stops filing the same quarter) — not a brand-new position.

Rows rank by the value each filer reported — 13F filers price their own positions, so a holder with fewer shares can rank just above one with more.

Holder trends· top 15 holders · shares held over 6 quarters

green added · red trimmed

Holder

2024-Q4

2025-Q1

2025-Q2

2025-Q3

2025-Q4

2026-Q1

Latest value

BlackRock, Inc.

11.7M

11.0M

10.9M

12.1M

11.1M

10.7M

$205M

Sessa Capital IM, L.P.

—

4.5M

5.0M

4.7M

$91M

VANGUARD PORTFOLIO MANAGEMENT LLC

—

4.0M

$77M

ArrowMark Colorado Holdings LLC

2.7M

3.7M

2.9M

3.1M

$59M

VANGUARD CAPITAL MANAGEMENT LLC

—

3.0M

$58M

GW&K Investment Management, LLC

2.1M

2.9M

2.7M

$52M

STATE STREET CORP

2.8M

2.7M

2.6M

2.7M

2.6M

2.7M

$51M

Driehaus Capital Management LLC

—

1.6M

2.3M

$44M

GOLDMAN SACHS GROUP INC

678K

713K

1.9M

1.4M

1.7M

2.2M

$43M

CITADEL ADVISORS LLC

132K

114K

353K

40K

2.1M

2.2M

$42M

UBS Group AG

626K

836K

1.4M

1.5M

418K

2.0M

$39M

Paradice Investment Management LLC

956K

1.6M

1.8M

2.2M

2.1M

2.0M

$39M

TWO SIGMA INVESTMENTS, LP

861K

641K

1.2M

1.1M

1.2M

1.9M

$36M

GEODE CAPITAL MANAGEMENT, LLC

1.5M

1.6M

1.7M

$32M

JENNISON ASSOCIATES LLC

1.5M

1.7M

1.4M

2.0M

1.7M

$32M

Shares reported each quarter by the largest current holders. Green = added vs the prior filing, red = trimmed, grey = roughly held; a dash is a quarter with no 13F on file (a gap is skipped, not read as an exit). 13F is filed up to 45 days after quarter-end. Up to 40 quarters (10 years) available — use the selector above.

Institutional footprint by quarter

Line breaks are honest gaps — quarters with no 13F record, or a suppressed % — never interpolated. % of shares outstanding uses today's share count for every quarter (the only count stored).

Quarter	Holders	Shares held	% shares out	Value held
2026-Q1	272	78,656,621	114.8%	$1.5B
2025-Q4	267	74,920,291	109.3%	$1.6B

Short interest has its own tab now — open SI →

Source: SEC Form 13F — every institution manager (≥ $100M in 13F securities) reporting a long US-listed position, across ~10,250 filers over 10 years of history. 13F is long-only, US-listed, filed up to 45 days after quarter-end.

Activists & large holders· Schedule 13D/G beneficial owners · TNDM

Large holders — 13G, passive (top 5 of 7 by % of class)

Holder

% of class

Type

As of

BlackRock, Inc.

15.2%

QII

2025-03-31

SEC →

Sessa Capital (Master), L.P.

6.71%

Passive

2025-03-31

SEC →

Voya Financial, Inc.

6.3%

QII

2026-03-31

SEC →

VANGUARD PORTFOLIO MANAGEMENT LLC

5.91%

QII

2026-03-31

SEC →

VANGUARD CAPITAL MANAGEMENT LLC

5.18%

QII

Institutional ownership· 13F filers holding TNDM · 2026-Q1 methodology → sources →

272 holders

% of shares outstanding held

114.8%

Shares held (13F)

78,656,621

Reporting holders

272

Top holders

largest 100 of 272 · Δ vs 2025-Q4

#	Holder	Shares	Value	% of shares out	Δ QoQ
1	BlackRock, Inc.	10,690,84410.7M	$205M	15.60%	TRIM -4%
2	Sessa Capital IM, L.P.	4,730,7574.7M	$91M	6.90%	TRIM -5%
3	VANGUARD PORTFOLIO MANAGEMENT LLC	3,993,3334.0M	$77M	5.83%	NEW†
4	ArrowMark Colorado Holdings LLC	3,103,6093.1M	$59M	4.53%	ADD 7%
5	VANGUARD CAPITAL MANAGEMENT LLC	3,038,9193.0M	$58M	4.43%	NEW†
6	GW&K Investment Management, LLC	2,689,1062.7M	$52M	3.92%	—
7	STATE STREET CORP	2,662,2602.7M	$51M	3.88%	—
8	Driehaus Capital Management LLC	2,304,4142.3M	$44M	3.36%	ADD 43%
9	GOLDMAN SACHS GROUP INC	2,218,9222.2M	$43M	3.24%	ADD 32%
10	CITADEL ADVISORS LLC	2,192,6672.2M	$42M	3.20%	ADD 5%
11	UBS Group AG	2,047,8012.0M	$39M	2.99%	ADD 390%
12	Paradice Investment Management LLC	2,042,4252.0M	$39M	2.98%	—
13	TWO SIGMA INVESTMENTS, LP	1,864,1941.9M	$36M	2.72%	ADD 55%
14	GEODE CAPITAL MANAGEMENT, LLC	1,679,8631.7M	$32M	2.45%	—
15	JENNISON ASSOCIATES LLC	1,658,4481.7M	$32M	2.42%	TRIM -18%
16	JACOBS LEVY EQUITY MANAGEMENT, INC	1,523,9461.5M	$29M	2.22%	TRIM -8%
17	MARSHALL WACE, LLP	1,442,4721.4M	$28M	2.10%	ADD 65%
18	MORGAN STANLEY	1,357,5421.4M	$26M	1.98%	TRIM -35%
19	Freestone Grove Partners LP	1,330,7421.3M	$26M	1.94%	TRIM -8%
20	First Light Asset Management, LLC	1,314,7151.3M	$25M	1.92%	ADD 21%
21	BAILLIE GIFFORD & CO	1,089,3931.1M	$21M	1.59%	TRIM -5%
22	WELLINGTON MANAGEMENT GROUP LLP	1,042,7641.0M	$20M	1.52%	ADD 961%
23	VOYA INVESTMENT MANAGEMENT LLC	804,137804,137	$15M	1.17%	ADD 152%
24	D. E. Shaw & Co., Inc.	783,906783,906	$15M	1.14%	TRIM -8%
25	Soleus Capital Management, L.P.	783,000783,000	$15M	1.14%	NEW
26	Defilade Capital Management, L.P.	761,905761,905	$15M	1.11%	NEW
27	MILLENNIUM MANAGEMENT LLC	761,672761,672	$15M	1.11%	ADD 31%
28	FMR LLC	714,011714,011	$14M	1.04%	ADD 6%
29	NORTHERN TRUST CORP	706,609706,609	$14M	1.03%	ADD 2%
30	ROYCE & ASSOCIATES LP	696,590696,590	$13M	1.02%	ADD 7%
31	Quantinno Capital Management LP	653,870653,870	$13M	0.95%	ADD 124%
32	CHARLES SCHWAB INVESTMENT MANAGEMENT INC	642,598642,598	$12M	0.94%	—
33	ExodusPoint Capital Management, LP	632,899632,899	$12M	0.92%	NEW
34	Holocene Advisors, LP	477,359477,359	$9M	0.70%	ADD 2808%
35	VANGUARD FIDUCIARY TRUST CO	471,658471,658	$9M	0.69%	NEW
36	Aberdeen Group plc	434,027434,027	$8M	0.63%	TRIM -21%
37	BARCLAYS PLC	421,236421,236	$8M	0.61%	TRIM -54%
38	Point72 Asset Management, L.P.	420,478420,478	$8M	0.61%	NEW
39	FRONTIER CAPITAL MANAGEMENT CO LLC	397,209397,209	$8M	0.58%	TRIM -4%
40	BANK OF AMERICA CORP /DE/	373,224373,224	$7M	0.54%	TRIM -47%
41	Nuveen, LLC	363,802363,802	$7M	0.53%	TRIM -35%
42	JPMORGAN CHASE & CO	349,792349,792	$7M	0.51%	ADD 2%
43	DAFNA Capital Management LLC	355,208355,208	$7M	0.52%	—
44	FIRST TRUST ADVISORS LP	342,707342,707	$7M	0.50%	NEW
45	Bank of New York Mellon Corp	336,291336,291	$6M	0.49%	TRIM -4%
46	AQR CAPITAL MANAGEMENT LLC	331,916331,916	$6M	0.48%	TRIM -2%
47	PRINCIPAL FINANCIAL GROUP INC	331,541331,541	$6M	0.48%	ADD 2%
48	Invesco Ltd.	294,052294,052	$6M	0.43%	ADD 6%
49	ACADIAN ASSET MANAGEMENT LLC	278,116278,116	$5M	0.41%	TRIM -29%
50	SECTOR GAMMA AS	267,091267,091	$5M	0.39%	—
51	EDMOND DE ROTHSCHILD HOLDING S.A.	258,200258,200	$5M	0.38%	—
52	BEACONLIGHT CAPITAL, LLC	253,877253,877	$5M	0.37%	NEW
53	Trexquant Investment LP	249,298249,298	$5M	0.36%	ADD 143%
54	ENVESTNET ASSET MANAGEMENT INC	243,248243,248	$5M	0.35%	ADD 10%
55	Public Sector Pension Investment Board	242,596242,596	$5M	0.35%	ADD 3%
56	BNP PARIBAS FINANCIAL MARKETS	208,713208,713	$4M	0.30%	TRIM -83%
57	Susquehanna Portfolio Strategies, LLC	206,193206,193	$4M	0.30%	ADD 210%
58	ROYAL BANK OF CANADA	206,033206,033	$4M	0.30%	—
59	ARROWSTREET CAPITAL, LIMITED PARTNERSHIP	193,556193,556	$4M	0.28%	ADD 43%
60	RHUMBLINE ADVISERS	186,316186,316	$4M	0.27%	—
61	Assenagon Asset Management S.A.	178,640178,640	$3M	0.26%	TRIM -85%
62	UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC	168,493168,493	$3M	0.25%	ADD 2%
63	Lisanti Capital Growth, LLC	165,325165,325	$3M	0.24%	TRIM -37%
64	PANAGORA ASSET MANAGEMENT INC	163,695163,695	$3M	0.24%	ADD 12%
65	MIZUHO MARKETS AMERICAS LLC	157,362157,362	$3M	0.23%	ADD 9%
66	Legal & General Group Plc	155,288155,288	$3M	0.23%	TRIM -10%
67	TORONTO DOMINION BANK	150,078150,078	$3M	0.22%	NEW
68	Russell Investments Group, Ltd.	133,596133,596	$3M	0.19%	ADD 4%
69	Swiss National Bank	133,300133,300	$3M	0.19%	—
70	RAYMOND JAMES FINANCIAL INC	125,345125,345	$2M	0.18%	ADD 4%
71	BANQUE PICTET & CIE SA	123,935123,935	$2M	0.18%	ADD 28%
72	FEDERATED HERMES, INC.	123,819123,819	$2M	0.18%	ADD 495176%
73	AMERIPRISE FINANCIAL INC	121,150121,150	$2M	0.18%	TRIM -6%
74	CANADA PENSION PLAN INVESTMENT BOARD	118,439118,439	$2M	0.17%	TRIM -33%
75	ALGERT GLOBAL LLC	117,799117,799	$2M	0.17%	ADD 8%
76	INTECH INVESTMENT MANAGEMENT LLC	111,421111,421	$2M	0.16%	ADD 307%
77	Verition Fund Management LLC	107,119107,119	$2M	0.16%	ADD 912%
78	SEI INVESTMENTS CO	95,30695,306	$2M	0.14%	TRIM -11%
79	Zurcher Kantonalbank (Zurich Cantonalbank)	94,34094,340	$2M	0.14%	ADD 27%
80	PDT Partners, LLC	93,80593,805	$2M	0.14%	TRIM -15%
81	Universal- Beteiligungs- und Servicegesellschaft mbH	87,35787,357	$2M	0.13%	—
82	CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM	84,25584,255	$2M	0.12%	ADD 31%
83	ALLIANCEBERNSTEIN L.P.	73,14973,149	$2M	0.11%	TRIM -69%
84	SUSQUEHANNA INTERNATIONAL GROUP, LLP	80,74980,749	$2M	0.12%	TRIM -38%
85	Nierenberg Investment Management Company, LLC	79,51079,510	$2M	0.12%	ADD 78%
86	TUDOR INVESTMENT CORP ET AL	78,99978,999	$2M	0.12%	TRIM -27%
87	Y-Intercept (Hong Kong) Ltd	77,87977,879	$1M	0.11%	TRIM -7%
88	Cerity Partners LLC	76,22876,228	$1M	0.11%	—
89	RICE HALL JAMES & ASSOCIATES, LLC	72,87872,878	$1M	0.11%	ADD 17%
90	FORMULA GROWTH LTD	70,82870,828	$1M	0.10%	—
91	PRUDENTIAL FINANCIAL INC	69,40469,404	$1M	0.10%	ADD 7%
92	PRICE T ROWE ASSOCIATES INC /MD/	68,66168,661	$1M	0.10%	ADD 21%
93	CITIGROUP INC	68,34668,346	$1M	0.10%	ADD 272%
94	NEW YORK STATE TEACHERS RETIREMENT SYSTEM	66,09666,096	$1M	0.10%	TRIM -3%
95	JONES FINANCIAL COMPANIES LLLP	58,38858,388	$1M	0.09%	ADD 3638%
96	Cinctive Capital Management LP	63,81263,812	$1M	0.09%	NEW
97	NATIXIS ADVISORS, LLC	61,08461,084	$1M	0.09%	ADD 7%
98	XTX Topco Ltd	60,82160,821	$1M	0.09%	NEW
99	DEUTSCHE BANK AG\	60,62960,629	$1M	0.09%	ADD 12%
100	VANGUARD ASSET MANAGEMENT, Ltd	58,28858,288	$1M	0.09%	NEW

† a filer this large appearing as NEW usually reflects a renamed or succeeded filing entity (the old name stops filing the same quarter) — not a brand-new position.

Rows rank by the value each filer reported — 13F filers price their own positions, so a holder with fewer shares can rank just above one with more.

Holder trends· top 15 holders · shares held over 6 quarters

green added · red trimmed

Holder

2024-Q4

2025-Q1

2025-Q2

2025-Q3

2025-Q4

2026-Q1

Latest value

BlackRock, Inc.

11.7M

11.0M

10.9M

12.1M

11.1M

10.7M

$205M

Sessa Capital IM, L.P.

—

4.5M

5.0M

4.7M

$91M

VANGUARD PORTFOLIO MANAGEMENT LLC

—

4.0M

$77M

ArrowMark Colorado Holdings LLC

2.7M

3.7M

2.9M

3.1M

$59M

VANGUARD CAPITAL MANAGEMENT LLC

—

3.0M

$58M

GW&K Investment Management, LLC

2.1M

2.9M

2.7M

$52M

STATE STREET CORP

2.8M

2.7M

2.6M

2.7M

2.6M

2.7M

$51M

Driehaus Capital Management LLC

—

1.6M

2.3M

$44M

GOLDMAN SACHS GROUP INC

678K

713K

1.9M

1.4M

1.7M

2.2M

$43M

CITADEL ADVISORS LLC

132K

114K

353K

40K

2.1M

2.2M

$42M

UBS Group AG

626K

836K

1.4M

1.5M

418K

2.0M

$39M

Paradice Investment Management LLC

956K

1.6M

1.8M

2.2M

2.1M

2.0M

$39M

TWO SIGMA INVESTMENTS, LP

861K

641K

1.2M

1.1M

1.2M

1.9M

$36M

GEODE CAPITAL MANAGEMENT, LLC

1.5M

1.6M

1.7M

$32M

JENNISON ASSOCIATES LLC

1.5M

1.7M

1.4M

2.0M

1.7M

$32M

Institutional footprint by quarter

Line breaks are honest gaps — quarters with no 13F record, or a suppressed % — never interpolated. % of shares outstanding uses today's share count for every quarter (the only count stored).

Quarter	Holders	Shares held	% shares out	Value held
2026-Q1	272	78,656,621	114.8%	$1.5B
2025-Q4	267	74,920,291	109.3%	$1.6B

Short interest has its own tab now — open SI →

Activists & large holders· Schedule 13D/G beneficial owners · TNDM

Large holders — 13G, passive (top 5 of 7 by % of class)

Holder

% of class

Type

As of

BlackRock, Inc.

15.2%

QII

2025-03-31

SEC →

Sessa Capital (Master), L.P.

6.71%

Passive

2025-03-31

SEC →

Voya Financial, Inc.

6.3%

QII

2026-03-31

SEC →

VANGUARD PORTFOLIO MANAGEMENT LLC

5.91%

QII

2026-03-31

SEC →

VANGUARD CAPITAL MANAGEMENT LLC

5.18%

QII

TNDM US Equity☆

Institutional ownership· 13F filers holding TNDM · 2026-Q1 methodology → sources →

Top holders

Holder trends· top 15 holders · shares held over 6 quarters

Institutional footprint by quarter

Activists & large holders· Schedule 13D/G beneficial owners · TNDM

Institutional ownership· 13F filers holding TNDM · 2026-Q1 methodology → sources →

Top holders

Holder trends· top 15 holders · shares held over 6 quarters

Institutional footprint by quarter

Activists & large holders· Schedule 13D/G beneficial owners · TNDM

TNDM US Equity