TANDEM DIABETES CARE INC (TNDM) — Institutional Holders, Q2 2026
294 institutional investment managers reported a TNDM position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $1.5B. Every filer is listed below, ranked by position value, 100 per page; this page shows ranks 1 to 100. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.
TNDM in Q2 2026: what funds did
Funds that filed a 13F for both Q1 2026 and Q2 2026, by what they did with the common stock. Share counts are adjusted for any split between the two quarters; dollar figures are the change in shares at this quarter’s price.
Biggest buyers
- First Light Asset ManagementAdded · +2,068,838 sh+$31.2M
- Woodline PartnersNew · +1,307,439 sh+$19.7M
- BlackRockAdded · +892,281 sh+$13.5M
- JENNISON ASSOCIATESAdded · +672,981 sh+$10.2M
- Qube Research & Technologies LtdAdded · +631,862 sh+$9.5M
Biggest sellers
- ArrowMark ColoradoTrimmed · -1,804,023 sh-$27.2M
- MARSHALL WACE, LLPSold out · -1,442,472 sh-$21.8M
- GOLDMAN SACHS GROUPTrimmed · -1,356,621 sh-$20.5M
- TWO SIGMA INVESTMENTSTrimmed · -1,305,785 sh-$19.7M
- BAILLIE GIFFORDSold out · -1,089,393 sh-$16.4M
TNDM 13F holders ranked 1–100 of 294
| # | Institution | Shares | Value | % of portfolio | QoQShares vs Q1 2026 |
|---|---|---|---|---|---|
| 1 | BlackRock#1 · 18,608,125 sh | 18,608,125 | $181.4M | <0.01% | +17.5% |
| 2 | Sessa Capital IM, L.P.#2 · 5,100,000 sh | 5,100,000 | $77.0M | 1.29% | +7.8% |
| 3 | LINDEN ADVISORS#3 · 74,791,000 sh | 74,791,000 | $71.2M | 0.37% | +36.5% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT#4 · 4,299,667 sh | 4,299,667 | $64.9M | <0.01% | +7.7% |
| 5 | First Light Asset Management#5 · 3,383,553 sh | 3,383,553 | $51.1M | 3.10% | +157.4% |
| 6 | BANK OF MONTREAL#6 · 42,603,966 sh | 42,603,966 | $48.6M | 0.02% | +1.3% |
| 7 | VANGUARD CAPITAL MANAGEMENT#7 · 3,096,536 sh | 3,096,536 | $46.7M | <0.01% | +1.9% |
| 8 | STATE STREET#8 · 2,851,646 sh | 2,851,646 | $43.0M | <0.01% | +7.1% |
| 9 | GW&K Investment Management#9 · 2,569,032 sh | 2,569,032 | $38.8M | 0.30% | -4.5% |
| 10 | JENNISON ASSOCIATES#10 · 2,331,429 sh | 2,331,429 | $35.2M | 0.02% | +40.6% |
| 11 | Paradice Investment Management#11 · 2,024,014 sh | 2,024,014 | $30.5M | — | -0.9% |
| 12 | JACOBS LEVY EQUITY MANAGEMENT#12 · 2,006,429 sh | 2,006,429 | $30.3M | 0.11% | +31.7% |
| 13 | Freestone Grove Partners#13 · 1,866,134 sh | 1,866,134 | $28.2M | 0.18% | +40.2% |
| 14 | GEODE CAPITAL MANAGEMENT#14 · 1,800,797 sh | 1,800,797 | $27.2M | <0.01% | +7.2% |
| 15 | DRIEHAUS CAPITAL MANAGEMENT#15 · 1,786,996 sh | 1,786,996 | $27.0M | 0.16% | -22.5% |
| 16 | Opti Capital Management#16 · 27,500,000 sh | 27,500,000 | $26.4M | 1.61% | New |
| 17 | CITADEL ADVISORS#17 · 1,735,879 sh | 1,735,879 | $26.2M | <0.01% | -20.8% |
| 18 | BALYASNY ASSET MANAGEMENT L.P.#18 · 25,000,000 sh | 25,000,000 | $23.9M | 0.03% | New |
| 19 | GOLDMAN SACHS GROUP#19 · 11,305,301 sh | 11,305,301 | $22.9M | <0.01% | +409.5% |
| 20 | MILLENNIUM MANAGEMENT#20 · 1,311,739 sh | 1,311,739 | $19.8M | <0.01% | +72.2% |
| 21 | Woodline Partners#21 · 1,307,439 sh | 1,307,439 | $19.7M | 0.06% | New |
| 22 | ArrowMark Colorado#22 · 1,299,586 sh | 1,299,586 | $19.6M | 0.82% | -58.1% |
| 23 | FMR#23 · 4,762,432 sh | 4,762,432 | $18.3M | <0.01% | +5.2% |
| 24 | Empyrean Capital Partners#24 · 18,500,000 sh | 18,500,000 | $17.7M | 0.58% | New |
| 25 | UBS Group AG#25 · 1,146,580 sh | 1,146,580 | $17.3M | <0.01% | -44.0% |
| 26 | DeepCurrents Investment Group#26 · 17,804,000 sh | 17,804,000 | $16.9M | 0.51% | -7.8% |
| 27 | Fort Baker Capital Management#27 · 15,000,000 sh | 15,000,000 | $14.4M | 1.06% | New |
| 28 | Jump Financial#28 · 8,716,400 sh | 8,716,400 | $14.0M | 0.11% | New |
| 29 | ROYCE & ASSOCIATES#29 · 900,590 sh | 900,590 | $13.6M | 0.11% | +29.3% |
| 30 | WELLINGTON MANAGEMENT GROUP LLP#30 · 871,811 sh | 871,811 | $13.2M | <0.01% | -16.4% |
| 31 | NORTHERN#31 · 753,690 sh | 753,690 | $11.4M | <0.01% | +6.7% |
| 32 | Verition Fund Management#32 · 700,000 sh | 700,000 | $10.6M | 0.01% | +553.5% |
| 33 | ExodusPoint Capital Management#33 · 691,789 sh | 691,789 | $10.4M | 0.07% | +9.3% |
| 34 | Qube Research & Technologies Ltd#34 · 683,823 sh | 683,823 | $10.3M | <0.01% | +1216.0% |
| 35 | D. E. Shaw#35 · 681,808 sh | 681,808 | $10.3M | <0.01% | -13.0% |
| 36 | ARROWSTREET CAPITAL, LIMITED PARTNERSHIP#36 · 667,689 sh | 667,689 | $10.1M | <0.01% | +245.0% |
| 37 | CHARLES SCHWAB INVESTMENT MANAGEMENT#37 · 656,836 sh | 656,836 | $9.9M | <0.01% | +2.2% |
| 38 | MORGAN STANLEY#38 · 647,069 sh | 647,069 | $9.8M | <0.01% | -52.3% |
| 39 | Point72 Asset Management, L.P.#39 · 610,903 sh | 610,903 | $9.2M | 0.01% | -92.3% |
| 40 | Soleus Capital Management, L.P.#40 · 575,000 sh | 575,000 | $8.7M | 0.30% | -26.6% |
| 41 | TWO SIGMA INVESTMENTS#41 · 558,409 sh | 558,409 | $8.4M | <0.01% | -70.0% |
| 42 | Calamos Advisors#42 · 8,550,000 sh | 8,550,000 | $8.2M | 0.03% | 0.0% |
| 43 | AQR CAPITAL MANAGEMENT#43 · 533,837 sh | 533,837 | $8.1M | <0.01% | +60.8% |
| 44 | VANGUARD FIDUCIARY#44 · 491,103 sh | 491,103 | $7.4M | <0.01% | +4.1% |
| 45 | abrdn plc#45 · 441,738 sh | 441,738 | $6.7M | <0.01% | +1.8% |
| 46 | BANK OF AMERICA#46 · 395,054 sh | 395,054 | $6.0M | <0.01% | +5.8% |
| 47 | ADVENT CAPITAL MANAGEMENT#47 · 6,196,000 sh | 6,196,000 | $5.9M | 0.13% | New |
| 48 | FRONTIER CAPITAL MANAGEMENT#48 · 380,458 sh | 380,458 | $5.7M | 0.05% | -4.2% |
| 49 | ARISTEIA CAPITAL, L.L.C.#49 · 6,000,000 sh | 6,000,000 | $5.7M | 0.07% | -40.0% |
| 50 | CITIGROUP#50 · 5,303,230 sh | 5,303,230 | $5.6M | <0.01% | +2274.4% |
| 51 | Bank of New York Mellon#51 · 602,161 sh | 602,161 | $5.6M | <0.01% | +79.1% |
| 52 | JPMORGAN CHASE#52 · 349,652 sh | 349,652 | $5.5M | <0.01% | 0.0% |
| 53 | TUDOR INVESTMENT ET AL#53 · 362,708 sh | 362,708 | $5.5M | <0.01% | +359.1% |
| 54 | DAFNA Capital Management#54 · 355,208 sh | 355,208 | $5.4M | 1.02% | 0.0% |
| 55 | BARCLAYS PLC#55 · 350,429 sh | 350,429 | $5.3M | <0.01% | -16.8% |
| 56 | PRINCIPAL FINANCIAL GROUP#56 · 335,094 sh | 335,094 | $5.1M | <0.01% | +1.1% |
| 57 | Invesco Ltd.#57 · 321,128 sh | 321,128 | $4.8M | <0.01% | +9.2% |
| 58 | Y-Intercept (Hong Kong) Ltd#58 · 314,653 sh | 314,653 | $4.7M | — | +304.0% |
| 59 | Alberta Investment Management#59 · 313,700 sh | 313,700 | $4.7M | 0.03% | New |
| 60 | EDMOND DE ROTHSCHILD HOLDING S.A.#60 · 308,200 sh | 308,200 | $4.7M | 0.06% | +19.4% |
| 61 | Quantinno Capital Management#61 · 306,660 sh | 306,660 | $4.6M | <0.01% | -53.1% |
| 62 | KVP Capital Advisors#62 · 301,000 sh | 301,000 | $4.5M | 3.33% | New |
| 63 | Meridiem Capital Partners#63 · 298,255 sh | 298,255 | $4.5M | 0.20% | New |
| 64 | FIRST ADVISORS#64 · 292,844 sh | 292,844 | $4.4M | <0.01% | -14.5% |
| 65 | Holocene Advisors#65 · 267,860 sh | 267,860 | $4.0M | <0.01% | -43.9% |
| 66 | SECTOR GAMMA AS#66 · 267,091 sh | 267,091 | $4.0M | 0.87% | 0.0% |
| 67 | BEACONLIGHT CAPITAL#67 · 266,009 sh | 266,009 | $4.0M | 1.42% | +4.8% |
| 68 | LEUCADIA NATIONAL#68 · 1,266,489 sh | 1,266,489 | $3.6M | 0.02% | +2132.8% |
| 69 | ENVESTNET ASSET MANAGEMENT#69 · 235,966 sh | 235,966 | $3.6M | <0.01% | -3.0% |
| 70 | ALGERT GLOBAL#70 · 235,739 sh | 235,739 | $3.6M | 0.04% | +100.1% |
| 71 | PUBLIC SECTOR PENSION INVESTMENT BOARD#71 · 235,458 sh | 235,458 | $3.6M | <0.01% | -2.9% |
| 72 | ROYAL BANK OF CANADA#72 · 232,174 sh | 232,174 | $3.4M | <0.01% | +12.7% |
| 73 | Walleye Capital#73 · 3,500,000 sh | 3,500,000 | $3.3M | 0.01% | New |
| 74 | Squarepoint Ops#74 · 217,386 sh | 217,386 | $3.3M | <0.01% | New |
| 75 | XTX Topco Ltd#75 · 212,976 sh | 212,976 | $3.2M | 0.04% | +250.2% |
| 76 | Connor, Clark & Lunn Investment Management Ltd.#76 · 184,073 sh | 184,073 | $2.8M | <0.01% | New |
| 77 | SG Americas Securities#77 · 33,795 sh | 33,795 | $2.5M | <0.01% | +2.3% |
| 78 | RHUMBLINE ADVISERS#78 · 164,053 sh | 164,053 | $2.5M | <0.01% | -11.9% |
| 79 | Nierenberg Investment Management Company#79 · 158,910 sh | 158,910 | $2.4M | 1.19% | +99.9% |
| 80 | ZAZOVE ASSOCIATES#80 · 2,500,000 sh | 2,500,000 | $2.4M | 0.19% | New |
| 81 | TENOR CAPITAL MANAGEMENT , L.P.#81 · 2,500,000 sh | 2,500,000 | $2.4M | 0.03% | New |
| 82 | CSS#82 · 2,500,000 sh | 2,500,000 | $2.4M | 0.09% | New |
| 83 | CAPSTONE INVESTMENT ADVISORS#83 · 2,500,000 sh | 2,500,000 | $2.4M | <0.01% | New |
| 84 | Nuveen#84 · 157,066 sh | 157,066 | $2.4M | <0.01% | -56.8% |
| 85 | Legal & General Group Plc#85 · 155,749 sh | 155,749 | $2.4M | <0.01% | +0.3% |
| 86 | UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AME#86 · 151,847 sh | 151,847 | $2.3M | <0.01% | -9.9% |
| 87 | Russell Investments Group, Ltd.#87 · 148,584 sh | 148,584 | $2.2M | <0.01% | +11.2% |
| 88 | Banco Santander, S.A.#88 · 147,200 sh | 147,200 | $2.2M | 0.01% | +974.5% |
| 89 | VOYA INVESTMENT MANAGEMENT#89 · 142,597 sh | 142,597 | $2.2M | <0.01% | -99.9% |
| 90 | MIZUHO MARKETS AMERICAS#90 · 137,762 sh | 137,762 | $2.1M | 0.03% | -12.5% |
| 91 | Swiss National Bank#91 · 137,500 sh | 137,500 | $2.1M | <0.01% | +3.2% |
| 92 | ACADIAN ASSET MANAGEMENT#92 · 137,237 sh | 137,237 | $2.1M | <0.01% | -50.7% |
| 93 | Schonfeld Strategic Advisors#93 · 129,567 sh | 129,567 | $2.0M | <0.01% | New |
| 94 | FEDERATED HERMES#94 · 123,819 sh | 123,819 | $1.9M | <0.01% | 0.0% |
| 95 | RAYMOND JAMES FINANCIAL#95 · 122,021 sh | 122,021 | $1.8M | <0.01% | -2.7% |
| 96 | SUSQUEHANNA INTERNATIONAL GROUP, LLP#96 · 117,958 sh | 117,958 | $1.8M | <0.01% | +46.1% |
| 97 | AMERIPRISE FINANCIAL#97 · 113,522 sh | 113,522 | $1.7M | <0.01% | -6.3% |
| 98 | BANQUE PICTET & CIE SA#98 · 112,335 sh | 112,335 | $1.7M | — | -9.4% |
| 99 | GABELLI FUNDS#99 · 103,000 sh | 103,000 | $1.6M | <0.01% | +312.0% |
| 100 | Trexquant Investment#100 · 90,058 sh | 90,058 | $1.4M | <0.01% | -63.9% |
Funds that sold out of TNDM in Q2 2026 (44)
Held TNDM at the end of Q1 2026 and filed a Q2 2026 13F without it. Not in the list above, because they no longer hold it. Largest prior position first.
| Institution | Shares sold | Value in Q1 2026 |
|---|---|---|
| MARSHALL WACE, LLP1,442,472 sh | 1,442,472 | $27.7M |
| BAILLIE GIFFORD1,089,393 sh | 1,089,393 | $20.9M |
| Defilade Capital Management, L.P.761,905 sh | 761,905 | $14.6M |
| Lisanti Capital Growth165,325 sh | 165,325 | $3.2M |
| PANAGORA ASSET MANAGEMENT163,695 sh | 163,695 | $3.1M |
| TORONTO DOMINION BANK150,078 sh | 150,078 | $2.9M |
| CANADA PENSION PLAN INVESTMENT BOARD118,439 sh | 118,439 | $2.3M |
| RICE HALL JAMES & ASSOCIATES72,878 sh | 72,878 | $1.4M |
| RENAISSANCE TECHNOLOGIES58,227 sh | 58,227 | $1.1M |
| TWINBEECH CAPITAL51,366 sh | 51,366 | $984.7K |
| Legato Capital Management50,085 sh | 50,085 | $960.1K |
| IEQ CAPITAL39,007 sh | 39,007 | $747.8K |
| AMERICAN CENTURY COMPANIES33,470 sh | 33,470 | $641.6K |
| Dynamic Technology Lab Private Ltd27,886 sh | 27,886 | $534.6K |
| VARCOV26,562 sh | 26,562 | $509.2K |
| Diversified21,332 sh | 21,332 | $408.9K |
| Focus Partners Wealth17,534 sh | 17,534 | $336.5K |
| EVERGREEN CAPITAL MANAGEMENT12,992 sh | 12,992 | $249.1K |
| Counterpoint Mutual Funds12,679 sh | 12,679 | $243.1K |
| DRW Securities12,419 sh | 12,419 | $238.1K |
| EP Wealth Advisors11,886 sh | 11,886 | $227.9K |
| SYON CAPITAL11,437 sh | 11,437 | $219.2K |
| PARK AVENUE SECURITIES10,647 sh | 10,647 | $204.0K |
| ProShare Advisors10,554 sh | 10,554 | $202.3K |
| Apollon Wealth Management10,534 sh | 10,534 | $201.9K |
| Advisory Services Network8,274 sh | 8,274 | $158.6K |
| NATIXIS5,500 sh | 5,500 | $105.4K |
| QUADRANT CAPITAL GROUP960 sh | 960 | $58.2K |
| VAN ECK ASSOCIATES2,918 sh | 2,918 | $56.0K |
| SIMPLEX TRADING2,903 sh | 2,903 | $55.6K |
| OP Asset Management Ltd1,835 sh | 1,835 | $35.2K |
| GROUP ONE TRADING, L.P.1,815 sh | 1,815 | $34.8K |
| Ancora Advisors1,230 sh | 1,230 | $23.6K |
| Kemnay Advisory Services538 sh | 538 | $10.3K |
| BEACON INVESTMENT ADVISORY SERVICES240 sh | 240 | $4.6K |
| TWIN PEAKS WEALTH ADVISORS142 sh | 142 | $2.7K |
| Western Wealth Management140 sh | 140 | $2.7K |
| Newbridge Financial Services Group120 sh | 120 | $2.3K |
| MAI Capital Management113 sh | 113 | $2.2K |
| JPL Wealth Management61 sh | 61 | $1.2K |
| Golden State Equity Partners40 sh | 40 | $766.00 |
| Bell Investment Advisors36 sh | 36 | $691.00 |
| Root Financial Partners14 sh | 14 | $268.00 |
| Abound Wealth Management5 sh | 5 | $96.00 |
Source: Form 13F-HR filings on SEC EDGAR, Q2 2026. Values are as reported by each manager at quarter end. “% of portfolio” is the position’s share of the manager’s total reported 13F value for the same quarter. “New” means the manager filed a 13F for Q1 2026 without this position; a dash means no comparison is available. Where a manager’s own filing is internally inconsistent its value is withheld and it is listed last. 13F data shows reported holdings, not recommendations.