TANDEM DIABETES CARE INC (TNDM) Institutional Ownership Changes & 13F Activity
TANDEM DIABETES CARE INC (TNDM). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q2 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include First Light Asset Management, Llc, Goldman Sachs Group Inc, Woodline Partners Lp, Two Sigma Investments, Lp, and Qube Research & Technologies Ltd.
| Institution | Type | Change in shares | Change Position % | Shares | Reported stock balance | Portfolio quarter | Filing date |
|---|---|---|---|---|---|---|---|
| Manufacturers Life Insurance Company, The | Sell | -238 | -0.8% | 28,484 | $429.82K | Q2 2026 | Sep 09, 2026 |
| Citadel Advisors Llc | Sell | -456,788 | -20.8% | 1,735,879 | $26.19M | Q2 2026 | Sep 02, 2026 |
| Corient Private Wealth Llc | Sell | -17,152 | -50.8% | 16,589 | $250.33K | Q2 2026 | Aug 27, 2026 |
| California State Teachers Retirement System | Sell | -7,028 | -8.3% | 77,227 | $1.17M | Q2 2026 | Aug 24, 2026 |
| Assenagon Asset Management S.A. | Sell | -152,210 | -85.2% | 26,430 | $398.83K | Q2 2026 | Aug 21, 2026 |
| Mercer Global Advisors Inc | Sell | -3,800 | -18.8% | 16,412 | $247.66K | Q2 2026 | Aug 19, 2026 |
| Archer Investment Corp | Buy | +45 | — | 45 | $679.00 | Q2 2026 | Aug 19, 2026 |
| Fulcrum Asset Management Llp | Buy | +280 | — | 280 | $4.43K | Q2 2026 | Aug 18, 2026 |
| Jefferies Financial Group Inc. | Buy | +109,767 | +193.5% | 166,489 | $2.51M | Q2 2026 | Aug 17, 2026 |
| Proficio Capital Partners Llc | Buy | +11,897 | — | 11,897 | $179.53K | Q2 2026 | Aug 17, 2026 |
| Formula Growth Ltd | Sell | -524 | -0.7% | 70,304 | $1.06M | Q2 2026 | Aug 17, 2026 |
| Transamerica Financial Advisors, Llc | Sell | -372 | -95.6% | 17 | $256.00 | Q2 2026 | Aug 17, 2026 |
| First Light Asset Management, Llc | Buy | +2,068,838 | +157.4% | 3,383,553 | $51.06M | Q2 2026 | Aug 14, 2026 |
| Goldman Sachs Group Inc | Sell | -1,356,621 | -61.1% | 862,301 | $13.01M | Q2 2026 | Aug 14, 2026 |
| Woodline Partners Lp | Buy | +1,307,439 | — | 1,307,439 | $19.73M | Q2 2026 | Aug 14, 2026 |
| Two Sigma Investments, Lp | Sell | -1,305,785 | -70.0% | 558,409 | $8.43M | Q2 2026 | Aug 14, 2026 |
| Qube Research & Technologies Ltd | Buy | +631,862 | +1216.0% | 683,823 | $10.32M | Q2 2026 | Aug 14, 2026 |
| Verition Fund Management Llc | Buy | +592,881 | +553.5% | 700,000 | $10.56M | Q2 2026 | Aug 14, 2026 |
| Millennium Management Llc | Buy | +550,067 | +72.2% | 1,311,739 | $19.79M | Q2 2026 | Aug 14, 2026 |
| Freestone Grove Partners Lp | Buy | +535,392 | +40.2% | 1,866,134 | $28.16M | Q2 2026 | Aug 14, 2026 |
| Driehaus Capital Management Llc | Sell | -517,418 | -22.5% | 1,786,996 | $26.97M | Q2 2026 | Aug 14, 2026 |
| Jacobs Levy Equity Management, Inc | Buy | +482,483 | +31.7% | 2,006,429 | $30.28M | Q2 2026 | Aug 14, 2026 |
| Sessa Capital Im, L.P. | Buy | +369,243 | +7.8% | 5,100,000 | $76.96M | Q2 2026 | Aug 14, 2026 |
| Invesco Ltd. | Buy | +321,128 | — | 321,128 | $4.85M | Q2 2026 | Aug 14, 2026 |
| Meridiem Capital Partners Lp | Buy | +298,255 | — | 298,255 | $4.50M | Q2 2026 | Aug 14, 2026 |
| Tudor Investment Corp Et Al | Buy | +283,709 | +359.1% | 362,708 | $5.47M | Q2 2026 | Aug 14, 2026 |
| Squarepoint Ops Llc | Buy | +217,386 | — | 217,386 | $3.28M | Q2 2026 | Aug 14, 2026 |
| Holocene Advisors, Lp | Sell | -209,499 | -43.9% | 267,860 | $4.04M | Q2 2026 | Aug 14, 2026 |
| Royce & Associates Lp | Buy | +204,000 | +29.3% | 900,590 | $13.59M | Q2 2026 | Aug 14, 2026 |
| Aqr Capital Management Llc | Buy | +201,921 | +60.8% | 533,837 | $8.06M | Q2 2026 | Aug 14, 2026 |
Frequently asked questions about TNDM activity
Which institutional owners are buying TNDM?
Institutional owners buying TNDM include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in TNDM activity?
"Buy" means an investor increased their reported position in TNDM compared to the prior reporting period. This reflects growing exposure to TANDEM DIABETES CARE INC (TNDM) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in TNDM increasing?
Institutional interest in TNDM can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.
Related TNDM Institutional Insights
- TNDM Overview
- TNDM 13F Institutional Holders
- TNDM Top Institutional Shareholders
- Healthcare Sector Institutional Ownership
- Healthcare Sector Portfolio Overlap
- Institutional Portfolio Overlap & Shared Holdings
- Most Bought Healthcare Stocks By Institutional Investors
- Most Sold Healthcare Stocks By Institutional Investors
- TNDM Insider Trading & SEC Form 4 Activity
- TNDM Articles
- Top Institutional Investor Stock Rankings