Tandem Diabetes Care TNDM Institutional Ownership

NASDAQ TNDM

$16.35 -0.17 (-1.03%)

At close: Oct 21, 2026 · 4:00 PM EDT

Institutions by Trading Activity

275 Institutions

Increased 145 52.7%

Unchanged 41 14.9%

Reduced 89 32.4%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

—

13F totals exceed reported shares outstanding

Shares Held by Institutions

78.74Mn

of 69.54Mn outstanding

▲+0.08% QoQ

Shares Outstanding

69.54Mn

Institutional Investors

275

filed 13F for Jun 2026

▲+2 vs prior quarter

Net Shares Added (QoQ)

+59.87K

accumulated since last quarter

Value of Holdings

$1.30Bn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Tandem Diabetes Care Inc (NASDAQ:TNDM) was reported as a holding by 275 institutional investors in 13F filings for the quarter ended June 30, 2026.

Total shares held in TNDM rose 0.08% from Q1 2026; the number of holders rose 3.00% from Q2 2025.
Of the 275 holders, 145 added to their positions, 89 reduced their stakes and 41 left their positions unchanged in Q2 2026.
Institutional investors held 78.74Mn shares of Tandem Diabetes Care in total at the end of Q2 2026, up 59.87K from the prior quarter and down 372.45K from a year earlier.
BlackRock, Inc. led 13F holders of TNDM with 11.58Mn shares as of June 30, 2026.
Among holders that already owned Tandem Diabetes Care, the biggest buyers in Q2 2026 were First Light Asset Management, LLC (+2.07Mn shares), BlackRock, Inc. (+892.28K shares), Jennison Associates LLC (+672.98K shares), Qube Research & Technologies Ltd (+631.86K shares) and Verition Fund Management LLC (+592.88K shares).
Among holders that kept a stake in Tandem Diabetes Care, the biggest sellers in Q2 2026 were ArrowMark Colorado Holdings LLC (-1.8Mn shares), Goldman Sachs Group Inc (-1.36Mn shares), Two Sigma Investments, LP (-1.31Mn shares), UBS Group AG (-901.22K shares) and Morgan Stanley (-710.47K shares).
According to Business Quant data, the leading holders of TNDM for Q2 2026 were BlackRock, Inc. (11.58Mn shares), Sessa Capital IM, L.P. (5.1Mn shares), Vanguard Portfolio Management LLC (4.3Mn shares), First Light Asset Management, LLC (3.38Mn shares), Vanguard Capital Management LLC (3.1Mn shares), State Street Corp (2.85Mn shares), GW&K Investment Management, LLC (2.57Mn shares), Jennison Associates LLC (2.33Mn shares), Paradice Investment Management LLC (2.02Mn shares) and Jacobs Levy Equity Management, Inc (2.01Mn shares).

Form 13F Holdings

275 Institutional Holders

Report period 30 Jun, 2026

Total shares held 78.74Mn

Of outstanding —

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	11,583,125	16.66%	▲892,281	+8.35%	$174.79Mn
2	Sessa Capital IM, L.P.	0001595849	5,100,000	7.33%	▲369,243	+7.81%	$76.96Mn
3	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	4,299,667	6.18%	▲306,334	+7.67%	$64.88Mn
4	First Light Asset Management, LLC	0001600004	3,383,553	4.87%	▲2,068,838	+157.36%	$51.06Mn
5	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	3,096,536	4.45%	▲57,617	+1.90%	$46.73Mn
6	State Street Corp	0000093751	2,851,646	4.10%	▲189,386	+7.11%	$43.03Mn
7	GW&K Investment Management, LLC	0001082917	2,569,032	3.69%	▼120,074	-4.47%	$38.77K
8	JENNISON ASSOCIATES LLC	0000053417	2,331,429	3.35%	▲672,981	+40.58%	$35.18Mn
9	Paradice Investment Management LLC	0001620275	2,024,014	2.91%	▼18,411	-0.90%	$30.54Mn
10	JACOBS LEVY EQUITY MANAGEMENT, INC	0000884414	2,006,429	2.89%	▲482,483	+31.66%	$30.28Mn
11	Freestone Grove Partners LP	0002007591	1,866,134	2.68%	▲535,392	+40.23%	$28.16Mn
12	GEODE CAPITAL MANAGEMENT, LLC	0001214717	1,800,797	2.59%	▲120,934	+7.20%	$27.18Mn
13	DRIEHAUS CAPITAL MANAGEMENT LLC	0000938206	1,786,996	2.57%	▼517,418	-22.45%	$26.97Mn
14	CITADEL ADVISORS LLC	0001423053	1,735,879	2.50%	▼456,788	-20.83%	$26.19Mn
15	MILLENNIUM MANAGEMENT LLC	0001273087	1,311,739	1.89%	▲550,067	+72.22%	$19.79Mn
16	Woodline Partners LP	0001784547	1,307,439	1.88%	▲1,307,439	0.00%	$19.73Mn
17	ArrowMark Colorado Holdings LLC	0001483859	1,299,586	1.87%	▼1,804,023	-58.13%	$19.61Mn
18	UBS Group AG	0001610520	1,146,580	1.65%	▼901,221	-44.01%	$17.30Mn
19	FMR LLC	0000315066	976,432	1.40%	▲262,421	+36.75%	$14.73Mn
20	ROYCE & ASSOCIATES LP	0000906304	900,590	1.30%	▲204,000	+29.29%	$13.59Mn

Showing 1 to 20 of 275 holders