Tandem Diabetes Care TNDM Institutional Ownership

NASDAQ TNDM

$16.43 +0.13 (+0.77%)

As of: Oct 1, 2026 · 3:38 PM EDT

Institutions by Trading Activity

276 Institutions

Increased 146 52.9%

Unchanged 41 14.9%

Reduced 89 32.2%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

115.04%

▲+0.02 pp QoQ

Shares Held by Institutions

79.39Mn

of 69.01Mn outstanding

▲+6.98% QoQ

Shares Outstanding

69.01Mn

-10.38Mn held outside 13F filers

Institutional Investors

276

filed 13F for Jun 2026

▲+2 vs prior quarter

Net Shares Added (QoQ)

+5.18Mn

accumulated since last quarter

Value of Holdings

$1.29Bn

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

Quarter ending 30 Jun, 2026

Tandem Diabetes Care Inc (NASDAQ:TNDM) appears in 276 institutional 13F filings for the quarter ending June 2026.

Their combined ownership stood at 115.0% of outstanding shares in June 2026, up from 115.0% in March 2026.
Their total shares held in TNDM increased 6.98% from the prior quarter, while the number of investors in Tandem Diabetes Care increased 2.6% year over year.
Activity in TNDM broke down as 146 buyers, 89 sellers, and 41 unchanged among 276 total holders.
Altogether, these fund groups held 79.39Mn shares in TNDM by June 2026, up by 5.18Mn shares quarter on quarter, and up 284.38K shares year over year.
BlackRock, Inc. is the top holder of Tandem Diabetes Care as of June 30, 2026, with 11.58Mn shares representing 16.78% of outstanding stock.
The largest buyers of Tandem Diabetes Care for the quarter ending June 2026 were First Light Asset Management, LLC (2.07Mn), Woodline Partners LP (1.31Mn), BlackRock, Inc. (892.28K), JENNISON ASSOCIATES LLC (672.98K), Sixth Street Partners Management Company, L.P. (656.84K).
Top sellers of TNDM stock for the quarter ending June 2026 included ArrowMark Colorado Holdings LLC (1.8Mn), Goldman Sachs Group Inc (1.36Mn), TWO SIGMA INVESTMENTS, LP (1.31Mn), UBS Group AG (901.22K), Morgan Stanley (710.47K).
Per Business Quant, the top 10 investors in TNDM for the quarter ending June 2026 include BlackRock, Inc. (11.58Mn), Sessa Capital IM, L.P. (5.1Mn), VANGUARD PORTFOLIO MANAGEMENT LLC (4.3Mn), First Light Asset Management, LLC (3.38Mn), VANGUARD CAPITAL MANAGEMENT LLC (3.1Mn), State Street Corp (2.85Mn), GW&K Investment Management, LLC (2.57Mn), JENNISON ASSOCIATES LLC (2.33Mn), Paradice Investment Management LLC (2.02Mn), JACOBS LEVY EQUITY MANAGEMENT, INC (2.01Mn).

Form 13F Holdings

276 Institutional Holders

Report period 30 Jun, 2026

Total shares held 79.39Mn

Of outstanding 115.04%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	11,583,125	16.78%	▲892,281	+8.35%	$174.79Mn
2	Sessa Capital IM, L.P.	0001595849	5,100,000	7.39%	▲369,243	+7.81%	$76.96Mn
3	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	4,299,667	6.23%	▲306,334	+7.67%	$64.88Mn
4	First Light Asset Management, LLC	0001600004	3,383,553	4.90%	▲2,068,838	+157.36%	$51.06Mn
5	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	3,096,536	4.49%	▲57,617	+1.90%	$46.73Mn
6	State Street Corp	0000093751	2,851,646	4.13%	▲189,386	+7.11%	$43.03Mn
7	GW&K Investment Management, LLC	0001082917	2,569,032	3.72%	▼120,074	-4.47%	$38.77K
8	JENNISON ASSOCIATES LLC	0000053417	2,331,429	3.38%	▲672,981	+40.58%	$35.18Mn
9	Paradice Investment Management LLC	0001620275	2,024,014	2.93%	▼18,411	-0.90%	$30.54Mn
10	JACOBS LEVY EQUITY MANAGEMENT, INC	0000884414	2,006,429	2.91%	▲482,483	+31.66%	$30.28Mn
11	Freestone Grove Partners LP	0002007591	1,866,134	2.70%	▲535,392	+40.23%	$28.16Mn
12	GEODE CAPITAL MANAGEMENT, LLC	0001214717	1,800,797	2.61%	▲120,934	+7.20%	$27.18Mn
13	DRIEHAUS CAPITAL MANAGEMENT LLC	0000938206	1,786,996	2.59%	▼517,418	-22.45%	$26.97Mn
14	CITADEL ADVISORS LLC	0001423053	1,735,879	2.52%	▼456,788	-20.83%	$26.19Mn
15	MILLENNIUM MANAGEMENT LLC	0001273087	1,311,739	1.90%	▲550,067	+72.22%	$19.79Mn
16	Woodline Partners LP	0001784547	1,307,439	1.89%	▲1,307,439	0.00%	$19.73Mn
17	ArrowMark Colorado Holdings LLC	0001483859	1,299,586	1.88%	▼1,804,023	-58.13%	$19.61Mn
18	UBS Group AG	0001610520	1,146,580	1.66%	▼901,221	-44.01%	$17.30Mn
19	FMR LLC	0000315066	976,432	1.41%	▲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 276 holders