Tandem Diabetes Care Inc: which funds bought and sold
Institutions that bought and sold Tandem Diabetes Care shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.
Between March 31, 2026 and June 30, 2026, 140 institutions that filed 13F reports for both quarters added to or opened positions in Tandem Diabetes Care, and 135 cut or closed them. Together they added a net 161K shares, +0.2% on what they held at the start of the quarter. Active managers and hedge funds on our list were net buyers of 1.4M shares (+5.1%); index fund managers were net buyers of 1.6M shares (+6.7%). 45 opened a new position and 44 sold out entirely.
Bought, Q2 2026 140 institutions, 45 of them new holders Sold, Q2 2026 135 institutions, 44 of them sold out
Net change, all compared +161K shares (+0.2%)
Net change, active managers +1.4M shares (+5.1%), 27 bought, 20 sold
Buyers versus sellers
140 bought 39 135 sold
Active managers and hedge funds 27 bought · 20 sold · +1.4M
Index fund managers 8 bought · 2 sold · +1.6M
Other institutions 105 bought · 113 sold · −2.8M
Biggest buyers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| First Light Asset Management, LLC | +2.1M +157.4% | 3.4M | $51.1M |
| Woodline Partners LP Hedge fund | +1.3M New position | 1.3M | $19.7M |
| Blackrock, Inc. Index funds | +892K +8.3% | 11.6M | $175M |
| Jennison Associates LLC Active manager | +673K +40.6% | 2.3M | $35.2M |
| Qube Research & Technologies Ltd Hedge fund | +632K +1216.0% | 684K | $10.3M |
| Verition Fund Management LLC Hedge fund | +593K +553.5% | 700K | $10.6M |
| Millennium Management LLC Hedge fund | +550K +72.2% | 1.3M | $19.8M |
| Freestone Grove Partners LP Hedge fund | +535K +40.2% | 1.9M | $28.2M |
| Bank Of Montreal | +528K +1409.2% | 565K | $8.5M |
| Jacobs Levy Equity Management, Inc Active manager | +482K +31.7% | 2.0M | $30.3M |
| Arrowstreet Capital, Limited Partnership Hedge fund | +474K +245.0% | 668K | $10.1M |
| Jump Financial, LLC | +404K New position | 404K | $6.1M |
| Sessa Capital Im, L.P. Hedge fund | +369K +7.8% | 5.1M | $77M |
| Alberta Investment Management Corp | +314K New position | 314K | $4.7M |
| Vanguard Portfolio Management LLC Index funds | +306K +7.7% | 4.3M | $64.9M |
| Kvp Capital Advisors, LP | +301K New position | 301K | $4.5M |
| Meridiem Capital Partners LP | +298K New position | 298K | $4.5M |
| Tudor Investment Corp Et Al Hedge fund | +284K +359.1% | 363K | $5.5M |
| FMR LLC Active manager | +262K +36.8% | 976K | $14.7M |
| Y-Intercept (Hong Kong) Ltd | +237K +304.0% | 315K | $4.7M |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Woodline Partners LP Hedge fund | +1.3M New position | 1.3M | $19.7M |
| Jennison Associates LLC Active manager | +673K +40.6% | 2.3M | $35.2M |
| Qube Research & Technologies Ltd Hedge fund | +632K +1216.0% | 684K | $10.3M |
| Verition Fund Management LLC Hedge fund | +593K +553.5% | 700K | $10.6M |
| Millennium Management LLC Hedge fund | +550K +72.2% | 1.3M | $19.8M |
| Freestone Grove Partners LP Hedge fund | +535K +40.2% | 1.9M | $28.2M |
| Jacobs Levy Equity Management, Inc Active manager | +482K +31.7% | 2.0M | $30.3M |
| Arrowstreet Capital, Limited Partnership Hedge fund | +474K +245.0% | 668K | $10.1M |
| Sessa Capital Im, L.P. Hedge fund | +369K +7.8% | 5.1M | $77M |
| Tudor Investment Corp Et Al Hedge fund | +284K +359.1% | 363K | $5.5M |
Biggest sellers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Arrowmark Colorado Holdings LLC | −1.8M −58.1% | 1.3M | $19.6M |
| Marshall Wace, LLP Hedge fund | −1.4M Sold out | 0 | — |
| Goldman Sachs Group Inc | −1.4M −61.1% | 862K | $13M |
| Two Sigma Investments, LP Hedge fund | −1.3M −70.0% | 558K | $8.4M |
| Baillie Gifford & Co Active manager | −1.1M Sold out | 0 | — |
| UBS Group AG | −901K −44.0% | 1.1M | $17.3M |
| Defilade Capital Management, L.P. | −762K Sold out | 0 | — |
| Morgan Stanley | −710K −52.3% | 647K | $9.8M |
| Voya Investment Management LLC | −662K −82.3% | 143K | $2.2M |
| Driehaus Capital Management LLC Active manager | −517K −22.5% | 1.8M | $27M |
| Citadel Advisors LLC Hedge fund | −457K −20.8% | 1.7M | $26.2M |
| Quantinno Capital Management LP | −347K −53.1% | 307K | $4.6M |
| Holocene Advisors, LP Hedge fund | −209K −43.9% | 268K | $4M |
| Soleus Capital Management, L.P. Hedge fund | −208K −26.6% | 575K | $8.7M |
| Nuveen, LLC | −207K −56.8% | 157K | $2.4M |
| Wellington Management Group LLP Active manager | −171K −16.4% | 872K | $13.2M |
| Lisanti Capital Growth, LLC | −165K Sold out | 0 | — |
| Panagora Asset Management Inc Active manager | −164K Sold out | 0 | — |
| Trexquant Investment LP Hedge fund | −159K −63.9% | 90K | $1.4M |
| Toronto Dominion Bank | −150K Sold out | 0 | — |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Marshall Wace, LLP Hedge fund | −1.4M Sold out | 0 | — |
| Two Sigma Investments, LP Hedge fund | −1.3M −70.0% | 558K | $8.4M |
| Baillie Gifford & Co Active manager | −1.1M Sold out | 0 | — |
| Driehaus Capital Management LLC Active manager | −517K −22.5% | 1.8M | $27M |
| Citadel Advisors LLC Hedge fund | −457K −20.8% | 1.7M | $26.2M |
| Holocene Advisors, LP Hedge fund | −209K −43.9% | 268K | $4M |
| Soleus Capital Management, L.P. Hedge fund | −208K −26.6% | 575K | $8.7M |
| Wellington Management Group LLP Active manager | −171K −16.4% | 872K | $13.2M |
| Panagora Asset Management Inc Active manager | −164K Sold out | 0 | — |
| Trexquant Investment LP Hedge fund | −159K −63.9% | 90K | $1.4M |
New positions
| Institution | Shares | Value June 30, 2026 |
|---|---|---|
| Woodline Partners LPHedge fund | 1.3M | $19.7M |
| Jump Financial, LLC | 404K | $6.1M |
| Alberta Investment Management Corp | 314K | $4.7M |
| Kvp Capital Advisors, LP | 301K | $4.5M |
| Meridiem Capital Partners LP | 298K | $4.5M |
| Squarepoint Ops LLCHedge fund | 217K | $3.3M |
| Connor, Clark & Lunn Investment Management Ltd. | 184K | $2.8M |
| Schonfeld Strategic Advisors LLCHedge fund | 130K | $2M |
| Cambridge Investment Research Advisors, Inc. | 105K | $1.6M |
| Fideuram - Intesa Sanpaolo Private Banking S.P.A. | 85K | $1.3M |
Sold out
| Institution | Shares | Value March 31, 2026 |
|---|---|---|
| Marshall Wace, LLPHedge fund | 1.4M | $27.7M |
| Baillie Gifford & CoActive manager | 1.1M | $20.9M |
| Defilade Capital Management, L.P. | 762K | $14.6M |
| Lisanti Capital Growth, LLC | 165K | $3.2M |
| Panagora Asset Management IncActive manager | 164K | $3.1M |
| Toronto Dominion Bank | 150K | $2.9M |
| Canada Pension Plan Investment Board | 118K | $2.3M |
| Rice Hall James & Associates, LLC | 73K | $1.4M |
| Renaissance Technologies LLCHedge fund | 58K | $1.1M |
| Twinbeech Capital LP | 51K | $984,686 |
Who holds the shares
- Institutions reporting
- 273
- Ten largest holders
- 49.8% of 13F-reported shares
- Index fund managers
- 32.6% of 13F-reported shares
- Active managers and hedge funds
- 36.2% of 13F-reported shares
| Type | Bought | Sold | New | Sold out | Net change in shares | Net % |
|---|---|---|---|---|---|---|
| Active managers and hedge funds | 27 | 20 | 6 | 5 | +1.4M | +5.1% |
| Index fund managers | 8 | 2 | 0 | 1 | +1.6M | +6.7% |
| Other institutions | 105 | 113 | 39 | 38 | −2.8M | −10.3% |