TNDM Tandem Diabetes Care, Inc.
Tandem Diabetes Care, Inc. (TNDM) Institutional Ownership
What the institutions did with TNDM last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.
Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.
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Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.
Largest holders
| Manager | Shares | % of reported |
|---|---|---|
| BlackRock, Inc. | 11.6M | 14.7% |
| Sessa Capital IM, L.P. | 5.1M | 6.5% |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 4.3M | 5.5% |
| First Light Asset Management, LLC | 3.4M | 4.3% |
| VANGUARD CAPITAL MANAGEMENT LLC | 3.1M | 3.9% |
| STATE STREET CORP | 2.9M | 3.6% |
| GW&K Investment Management, LLC | 2.6M | 3.3% |
| JENNISON ASSOCIATES LLC | 2.3M | 3.0% |
| Paradice Investment Management LLC | 2.0M | 2.6% |
| JACOBS LEVY EQUITY MANAGEMENT, INC | 2.0M | 2.5% |
| Freestone Grove Partners LP | 1.9M | 2.4% |
| GEODE CAPITAL MANAGEMENT, LLC | 1.8M | 2.3% |
| Driehaus Capital Management LLC | 1.8M | 2.3% |
| CITADEL ADVISORS LLC | 1.7M | 2.2% |
| MILLENNIUM MANAGEMENT LLC | 1.3M | 1.7% |
| Woodline Partners LP | 1.3M | 1.7% |
| ArrowMark Colorado Holdings LLC | 1.3M | 1.6% |
| UBS Group AG | 1.1M | 1.5% |
| FMR LLC | 976.4K | 1.2% |
| ROYCE & ASSOCIATES LP | 900.6K | 1.1% |
| WELLINGTON MANAGEMENT GROUP LLP | 871.8K | 1.1% |
| GOLDMAN SACHS GROUP INC | 862.3K | 1.1% |
| NORTHERN TRUST CORP | 753.7K | 1.0% |
| Verition Fund Management LLC | 700.0K | 0.9% |
| ExodusPoint Capital Management, LP | 691.8K | 0.9% |
Largest changes
| Manager | Action | Previous | Current | Change |
|---|---|---|---|---|
| First Light Asset Management, LLC | Increased | 1.3M | 3.4M | +2.1M |
| ArrowMark Colorado Holdings LLC | Reduced | 3.1M | 1.3M | -1.8M |
| MARSHALL WACE, LLP | Sold Out | 1.4M | 0 | -1.4M |
| GOLDMAN SACHS GROUP INC | Reduced | 2.2M | 862.3K | -1.4M |
| Woodline Partners LP | New | 0 | 1.3M | +1.3M |
| TWO SIGMA INVESTMENTS, LP | Reduced | 1.9M | 558.4K | -1.3M |
| BAILLIE GIFFORD & CO | Sold Out | 1.1M | 0 | -1.1M |
| UBS Group AG | Reduced | 2.0M | 1.1M | -901.2K |
| BlackRock, Inc. | Increased | 10.7M | 11.6M | +892.3K |
| Defilade Capital Management, L.P. | Sold Out | 761.9K | 0 | -761.9K |
| MORGAN STANLEY | Reduced | 1.4M | 647.1K | -710.5K |
| JENNISON ASSOCIATES LLC | Increased | 1.7M | 2.3M | +673.0K |
| VOYA INVESTMENT MANAGEMENT LLC | Reduced | 804.1K | 142.6K | -661.5K |
| Qube Research & Technologies Ltd | Increased | 52.0K | 683.8K | +631.9K |
| Verition Fund Management LLC | Increased | 107.1K | 700.0K | +592.9K |
| MILLENNIUM MANAGEMENT LLC | Increased | 761.7K | 1.3M | +550.1K |
| Freestone Grove Partners LP | Increased | 1.3M | 1.9M | +535.4K |
| BANK OF MONTREAL /CAN/ | Increased | 37.4K | 565.0K | +527.5K |
| Driehaus Capital Management LLC | Reduced | 2.3M | 1.8M | -517.4K |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Increased | 1.5M | 2.0M | +482.5K |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | Increased | 193.6K | 667.7K | +474.1K |
| CITADEL ADVISORS LLC | Reduced | 2.2M | 1.7M | -456.8K |
| Jump Financial, LLC | New | 0 | 404.4K | +404.4K |
| Sessa Capital IM, L.P. | Increased | 4.7M | 5.1M | +369.2K |
| Quantinno Capital Management LP | Reduced | 653.9K | 306.7K | -347.2K |
| Alberta Investment Management Corp | New | 0 | 313.7K | +313.7K |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Increased | 4.0M | 4.3M | +306.3K |
| KVP Capital Advisors, LP | New | 0 | 301.0K | +301.0K |
| Meridiem Capital Partners LP | New | 0 | 298.3K | +298.3K |
| TUDOR INVESTMENT CORP ET AL | Increased | 79.0K | 362.7K | +283.7K |
| FMR LLC | Increased | 714.0K | 976.4K | +262.4K |
| Y-Intercept (Hong Kong) Ltd | Increased | 77.9K | 314.7K | +236.8K |
| Squarepoint Ops LLC | New | 0 | 217.4K | +217.4K |
| Holocene Advisors, LP | Reduced | 477.4K | 267.9K | -209.5K |
| Soleus Capital Management, L.P. | Reduced | 783.0K | 575.0K | -208.0K |
| Nuveen, LLC | Reduced | 363.8K | 157.1K | -206.7K |
| ROYCE & ASSOCIATES LP | Increased | 696.6K | 900.6K | +204.0K |
| AQR CAPITAL MANAGEMENT LLC | Increased | 331.9K | 533.8K | +201.9K |
| Point72 Asset Management, L.P. | Increased | 420.5K | 610.9K | +190.4K |
| STATE STREET CORP | Increased | 2.7M | 2.9M | +189.4K |
| Connor, Clark & Lunn Investment Management Ltd. | New | 0 | 184.1K | +184.1K |
| WELLINGTON MANAGEMENT GROUP LLP | Reduced | 1.0M | 871.8K | -171.0K |
| Lisanti Capital Growth, LLC | Sold Out | 165.3K | 0 | -165.3K |
| PANAGORA ASSET MANAGEMENT INC | Sold Out | 163.7K | 0 | -163.7K |
| Trexquant Investment LP | Reduced | 249.3K | 90.1K | -159.2K |
| XTX Topco Ltd | Increased | 60.8K | 213.0K | +152.2K |
| TORONTO DOMINION BANK | Sold Out | 150.1K | 0 | -150.1K |
| BNP PARIBAS FINANCIAL MARKETS | Reduced | 208.7K | 63.2K | -145.5K |
| ACADIAN ASSET MANAGEMENT LLC | Reduced | 278.1K | 137.2K | -140.9K |
| Susquehanna Portfolio Strategies, LLC | Reduced | 206.2K | 68.9K | -137.3K |
| Banco Santander, S.A. | Increased | 13.7K | 147.2K | +133.5K |
| Schonfeld Strategic Advisors LLC | New | 0 | 129.6K | +129.6K |
| Assenagon Asset Management S.A. | Reduced | 178.6K | 52.9K | -125.8K |
| GEODE CAPITAL MANAGEMENT, LLC | Increased | 1.7M | 1.8M | +120.9K |
| GW&K Investment Management, LLC | Reduced | 2.7M | 2.6M | -120.1K |
| CANADA PENSION PLAN INVESTMENT BOARD | Sold Out | 118.4K | 0 | -118.4K |
| ALGERT GLOBAL LLC | Increased | 117.8K | 235.7K | +117.9K |
| Jefferies Financial Group Inc. | Increased | 56.7K | 166.5K | +109.8K |
| Cambridge Investment Research Advisors, Inc. | New | 0 | 104.6K | +104.6K |
| D. E. Shaw & Co., Inc. | Reduced | 783.9K | 681.8K | -102.1K |
13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.