TNDM · Tandem Diabetes Care Inc · Holdings
Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.
Institutional Ownership Trend
Holder Concentration
Across 275 13F filersWho Holds TNDM
Last 8 quarters through Sep 30, 2026 (filing window open)Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.
Jun 30, 2026, the newest closed quarter: 274 filers, like-for-like change +0.1%; actively managed books +1.9%; index-like books -3.7%.
| Holder type | Share | Filers | Change |
|---|---|---|---|
| Registered adviser | 59.9% | 136 | +7.0% |
| Exempt adviser | 1.3% | 3 | -35.5% |
| Adviser | 0.8% | 4 | -63.1% |
| Bank | 9.3% | 19 | -2.0% |
| Insurer | 0.5% | 3 | +7.6% |
| Broker-dealer | 0.1% | 1 | +36.8% |
| Benefit plan | 0.2% | 3 | +5.5% |
| Non-US | 0.9% | 7 | -1.9% |
| Holding company | 19.8% | 10 | -5.9% |
| Unknown | 7.1% | 88 | -5.8% |
| Style | Share | Filers | Change |
|---|---|---|---|
| Index-like | 30.8% | 33 | -3.7% |
| Systematic-like | 14.5% | 26 | +20.1% |
| Concentrated | 14.0% | 24 | +29.7% |
| Diversified active | 40.7% | 191 | -9.7% |
| Not measured | 0.0% | 0 | — |
| Unknown | 0.0% | 0 | — |
| Turnover | Share | Filers | Change |
|---|---|---|---|
| Low turnover | 37.8% | 141 | -5.4% |
| Medium turnover | 33.5% | 68 | +0.4% |
| High turnover | 18.0% | 45 | +13.5% |
| Unknown | 10.7% | 20 | -0.4% |
| Not measured | 0.0% | 0 | — |
| Holding horizon | Share | Filers | Change |
|---|---|---|---|
| Short horizon | 15.4% | 38 | +9.5% |
| Medium horizon | 17.4% | 37 | +7.0% |
| Long horizon | 47.7% | 175 | -9.4% |
| Unknown | 19.5% | 24 | +15.0% |
| Not measured | 0.0% | 0 | — |
| 13F book size | Share | Filers | Change |
|---|---|---|---|
| Under $1B | 4.6% | 50 | -13.9% |
| $1B to $10B | 16.8% | 76 | +14.1% |
| $10B to $100B | 23.1% | 83 | +12.0% |
| $100B or more | 55.5% | 65 | -6.3% |
| Not measured | 0.0% | 0 | — |
| Client base | Share | Filers | Change |
|---|---|---|---|
| Individuals and high net worth | 4.5% | 62 | -12.7% |
| Pooled investment vehicles | 25.9% | 33 | +27.8% |
| Registered funds and BDCs | 17.4% | 14 | +11.8% |
| Pension and profit sharing plans | 2.6% | 3 | -0.9% |
| Insurance companies | 0.2% | 3 | -77.6% |
| Governments and sovereign funds | 0.6% | 4 | -35.2% |
| Other investment advisers | 0.0% | 3 | -8.1% |
| Other | 0.1% | 1 | -0.6% |
| Diversified | 8.3% | 12 | -19.7% |
| Corporations | 0.0% | 0 | -100.0% |
| Unknown | 40.4% | 139 | -7.9% |
| Private funds | Share | Filers | Change |
|---|---|---|---|
| Hedge funds | 39.2% | 50 | +6.5% |
| Private equity funds | 0.2% | 9 | +6.1% |
| Venture capital funds | 0.0% | 1 | +102.3% |
| Real estate funds | 0.0% | 4 | +22.9% |
| Securitized asset funds | 0.2% | 1 | -9.9% |
| Other private funds | 8.2% | 14 | +17.5% |
| Mixed private funds | 0.1% | 1 | -4.2% |
| Private funds, type not stated | 0.0% | 3 | +294.8% |
| No private funds | 13.4% | 56 | -3.0% |
| Unknown | 38.7% | 135 | -7.5% |
| Location | Share | Filers | Change |
|---|---|---|---|
| United States | 91.5% | 221 | +2.3% |
| Outside the US | 8.5% | 53 | -18.6% |
The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.
How the mix is measured
Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.
Excluded 2 holders with no observed 2026-03-31 13F and 2 holders with no observed 2026-06-30 13F. Compared across CIK changes: JANUS HENDERSON GROUP PLC continues as Jupiter Topco LLC.
Conviction and Crowding
274 13F filers, quarter ended Jun 30, 2026Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.
Managers in the top fifth by current three-year FundScore alpha were net buyers of $0 (0 buying, 0 selling).
Estimated Holder Cost Basis
Quarter ended Jun 30, 2026, on that quarter's share basisEstimated, never filed: each 13F buy is costed at its quarter's average traded price and each sale keeps the average cost, so this is what holders paid on average if they traded evenly through each quarter.
Estimated cost covers 53.6% of the 13F shares; positions already held when a filer's 13F history starts, or bought in a quarter without a trusted average price, have no estimate.
Shared Holders
Companies TNDM's active holders also own, quarter ended Jun 30, 2026| # | Company | Shared holders |
|---|---|---|
| 1 | NPCE NeuroPace Inc | 3 |
| 2 | AXGN Axogen, Inc. | 5 |
| 3 | EWTX Edgewise Therapeutics, Inc. | 5 |
| 4 | ATRC AtriCure, Inc. | 3 |
| 5 | MBX MBX Biosciences, Inc. | 4 |
| 6 | NEO Neogenomics Inc | 3 |
| 7 | SNDX Syndax Pharmaceuticals Inc | 4 |
| 8 | PODD Insulet Corp | 5 |
| 9 | KURA Kura Oncology, Inc. | 3 |
| 10 | NKTR Nektar Therapeutics | 4 |
Shareholder Targets
13F filers that own its peers but not TNDM, quarter ended Jun 30, 2026Found through its holder-overlap peers: NPCE, AXGN, EWTX, ATRC, MBX, NEO, SNDX, PODD, KURA, NKTR, IDYA, IOVA, PRCT, WGS, CDNA, LIVN, VCEL, XENE, CRNX, VCYT. 1,067 filers in all.
| # | Filer | In peers | Largest peers |
|---|---|---|---|
| 1 | ORBIMED ADVISORS LLC Registered adviser, Diversified active | $1,001,145,045 7 held | EWTX, MBX, XENE |
| 2 | DIMENSIONAL FUND ADVISORS LP Registered adviser, Diversified active | $788,971,587 17 held | VCYT, LIVN, PODD |
| 3 | Artisan Partners Limited Partnership Registered adviser, Diversified active | $586,607,067 5 held | VCYT, LIVN, PODD |
| 4 | Polar Capital Holdings Plc Registered adviser, Diversified active | $571,507,031 5 held | XENE, MBX, CRNX |
| 5 | Paradigm Biocapital Advisors LP Registered adviser, Concentrated | $553,496,364 2 held | EWTX, MBX |
| 6 | T. Rowe Price Investment Management, Inc. Adviser, Diversified active | $527,833,144 5 held | PODD, XENE, CRNX |
| 7 | BAKER BROS. ADVISORS LP Registered adviser, Concentrated | $447,462,234 4 held | IDYA, EWTX, CRNX |
| 8 | Hood River Capital Management LLC Registered adviser, Diversified active | $433,852,462 5 held | LIVN, ATRC, SNDX |
| 9 | PRIMECAP MANAGEMENT CO/CA/ Registered adviser, Diversified active | $376,933,245 3 held | LIVN, NKTR, PODD |
| 10 | Frazier Life Sciences Management, L.P. Registered adviser, Concentrated | $367,191,117 1 held | MBX |
Fund Ownership of TNDM by Fund Type
Registered funds' Form N-PORT reports for the quarter ended Jun 30, 2026Index funds and index ETFs hold 28.35% of shares outstanding.
| Fund type | Of shares outstanding | Shares |
|---|---|---|
| Index funds | 4.75% | 3,305,914 |
| Index ETFs | 23.60% | 16,419,859 |
| Active ETFs | 0.85% | 590,387 |
| Active funds | 9.48% | 6,596,476 |
| Unclassified | 0.38% | 261,723 |
| All registered funds | 39.06% | 27,174,359 |
How fund types are measured
Each fund series counts once, with its latest Form N-PORT report dated inside the quarter; only long share positions count, restated to today's split basis. The fund type is the series' latest Form N-CEN answer on or before the quarter end (the index-fund box and the exchange-traded flag), never its name. Unclassified funds have no usable N-CEN; unit investment trusts are among them, so index ownership is a floor. Funds sit inside their advisers' 13F reports, so these shares overlap the 13F figures and are never added to them.
| Holder | Value (USD) | % of 13F | Shares | Type | Filed | Open |
|---|---|---|---|---|---|---|
| Mega BlackRock, Inc. Holding company | $174,789,349 | 13.64% | 11,583,125 | Shares | 2026-08-07 | |
| Mega UBS Group AG Bank | $78,144,621 | 6.10% | 5,178,570 | Call | 2026-08-13 | |
| Mid Sessa Capital IM, L.P. Registered adviser | $76,959,000 | 6.00% | 5,100,000 | Shares | 2026-08-14 | |
| Mega VANGUARD PORTFOLIO MANAGEMENT LLC Registered adviser | $64,881,975 | 5.06% | 4,299,667 | Shares | 2026-08-13 | |
| Mid First Light Asset Management, LLC Registered adviser | $51,057,814 | 3.98% | 3,383,553 | Shares | 2026-08-14 | |
| Mega VANGUARD CAPITAL MANAGEMENT LLC Registered adviser | $46,726,728 | 3.65% | 3,096,536 | Shares | 2026-08-13 | |
| Mega STATE STREET CORP Bank | $43,031,338 | 3.36% | 2,851,646 | Shares | 2026-09-22 | |
| Large GW&K Investment Management, LLC Registered adviser | $38,766,692 | 3.02% | 2,569,032 | Shares | 2026-08-12 | |
| Mega JENNISON ASSOCIATES LLC Registered adviser | $35,181,263 | 2.74% | 2,331,429 | Shares | 2026-08-03 | |
| Small Paradice Investment Management LLC Registered adviser | $32,740,938 | 2.55% | 2,007,415 | Shares | 2026-10-19 | |
| Large JACOBS LEVY EQUITY MANAGEMENT, INC Registered adviser | $30,277,013 | 2.36% | 2,006,429 | Shares | 2026-08-14 | |
| Large Freestone Grove Partners LP Registered adviser | $28,159,962 | 2.20% | 1,866,134 | Shares | 2026-08-14 | |
| Mega GEODE CAPITAL MANAGEMENT, LLC Registered adviser | $27,174,026 | 2.12% | 1,800,797 | Shares | 2026-08-12 | |
| Large Driehaus Capital Management LLC Registered adviser | $26,965,769 | 2.10% | 1,786,996 | Shares | 2026-08-14 | |
| Mega CITADEL ADVISORS LLC Registered adviser | $26,194,413 | 2.04% | 1,735,879 | Shares | 2026-09-02 | |
| Mega MILLENNIUM MANAGEMENT LLC Registered adviser | $19,794,141 | 1.54% | 1,311,739 | Shares | 2026-08-14 | |
| Large Woodline Partners LP Registered adviser | $19,729,254 | 1.54% | 1,307,439 | Shares | 2026-08-14 | |
| Mid ArrowMark Colorado Holdings LLC Registered adviser | $19,610,752 | 1.53% | 1,299,586 | Shares | 2026-08-13 | |
| Mega UBS Group AG Bank | $17,301,890 | 1.35% | 1,146,580 | Shares | 2026-08-13 | |
| Mega FMR LLC Holding company | $14,734,357 | 1.15% | 976,432 | Shares | 2026-08-13 | |
| Large ROYCE & ASSOCIATES LP Registered adviser | $13,589,903 | 1.06% | 900,590 | Shares | 2026-08-14 | |
| Mega WELLINGTON MANAGEMENT GROUP LLP Holding company | $13,155,625 | 1.03% | 871,811 | Shares | 2026-08-14 | |
| Mega GOLDMAN SACHS GROUP INC Holding company | $13,012,121 | 1.02% | 862,301 | Shares | 2026-08-14 | |
| Mega NORTHERN TRUST CORP Bank | $11,373,178 | 0.89% | 753,690 | Shares | 2026-08-13 | |
| Large Verition Fund Management LLC Registered adviser | $10,563,000 | 0.82% | 700,000 | Shares | 2026-08-14 | |
| Large ExodusPoint Capital Management, LP Registered adviser | $10,439,096 | 0.81% | 691,789 | Shares | 2026-08-14 | |
| Mega Qube Research & Technologies Ltd Exempt adviser | $10,318,889 | 0.80% | 683,823 | Shares | 2026-08-14 | |
| Mega D. E. Shaw & Co., Inc. | $10,288,482 | 0.80% | 681,808 | Shares | 2026-08-14 | |
| Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP Registered adviser | $10,075,427 | 0.79% | 667,689 | Shares | 2026-08-13 | |
| Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC Registered adviser | $9,911,655 | 0.77% | 656,836 | Shares | 2026-08-14 | |
| Mega MORGAN STANLEY Holding company | $9,764,268 | 0.76% | 647,069 | Shares | 2026-08-13 | |
| Large Point72 Asset Management, L.P. Registered adviser | $9,218,526 | 0.72% | 610,903 | Shares | 2026-08-14 | |
| Mid Soleus Capital Management, L.P. | $8,676,750 | 0.68% | 575,000 | Shares | 2026-08-11 | |
| Mega BANK OF MONTREAL /CAN/ Bank | $8,525,335 | 0.67% | 564,966 | Shares | 2026-08-12 | |
| Mega TWO SIGMA INVESTMENTS, LP Registered adviser | $8,426,391 | 0.66% | 558,409 | Shares | 2026-08-14 | |
| Mega AQR CAPITAL MANAGEMENT LLC Registered adviser | $8,055,598 | 0.63% | 533,837 | Shares | 2026-08-14 | |
| Mega VANGUARD FIDUCIARY TRUST CO | $7,410,744 | 0.58% | 491,103 | Shares | 2026-08-13 | |
| Large Aberdeen Group plc Holding company | $6,665,826 | 0.52% | 441,738 | Shares | 2026-07-31 | |
| Mid Jump Financial, LLC | $6,102,395 | 0.48% | 404,400 | Shares | 2026-08-13 | |
| Mega BANK OF AMERICA CORP /DE/ Bank | $5,961,362 | 0.47% | 395,054 | Shares | 2026-08-14 | |
| Large FRONTIER CAPITAL MANAGEMENT CO LLC Registered adviser | $5,741,111 | 0.45% | 380,458 | Shares | 2026-08-14 | |
| Large TUDOR INVESTMENT CORP ET AL Registered adviser | $5,473,263 | 0.43% | 362,708 | Shares | 2026-08-14 | |
| Small DAFNA Capital Management LLC Registered adviser | $5,360,088 | 0.42% | 355,208 | Shares | 2026-08-14 | |
| Mega Bank of New York Mellon Corp Bank | $5,314,106 | 0.41% | 352,161 | Shares | 2026-08-06 | |
| Mega BARCLAYS PLC Bank | $5,287,972 | 0.41% | 350,429 | Shares | 2026-08-14 | |
| Mega JPMORGAN CHASE & CO Bank | $5,276,247 | 0.41% | 349,652 | Shares | 2026-08-12 | |
| Mega PRINCIPAL FINANCIAL GROUP INC Insurer | $5,056,567 | 0.39% | 335,094 | Shares | 2026-08-04 | |
| Mega Invesco Ltd. Adviser | $4,845,819 | 0.38% | 321,128 | Shares | 2026-08-14 | |
| Large Alberta Investment Management Corp Non-US | $4,733,733 | 0.37% | 313,700 | Shares | 2026-08-06 | |
| Mid EDMOND DE ROTHSCHILD HOLDING S.A. | $4,650,738 | 0.36% | 308,200 | Shares | 2026-08-10 | |
| Large Quantinno Capital Management LP Registered adviser | $4,627,499 | 0.36% | 306,660 | Shares | 2026-08-13 | |
| Small KVP Capital Advisors, LP Registered adviser | $4,542,090 | 0.35% | 301,000 | Shares | 2026-08-13 | |
| Large Point72 Asset Management, L.P. Registered adviser | $4,527,000 | 0.35% | 300,000 | Call | 2026-08-14 | |
| Mid Meridiem Capital Partners LP Registered adviser | $4,500,667 | 0.35% | 298,255 | Shares | 2026-08-14 | |
| Mega FIRST TRUST ADVISORS LP Registered adviser | $4,419,015 | 0.34% | 292,844 | Shares | 2026-08-11 | |
| Large Holocene Advisors, LP Registered adviser | $4,042,007 | 0.32% | 267,860 | Shares | 2026-08-14 | |
| Small SECTOR GAMMA AS | $4,030,403 | 0.31% | 267,091 | Shares | 2026-08-12 | |
| Small BEACONLIGHT CAPITAL, LLC Registered adviser | $4,014,075 | 0.31% | 266,009 | Shares | 2026-08-14 | |
| Mega ENVESTNET ASSET MANAGEMENT INC Registered adviser | $3,560,726 | 0.28% | 235,966 | Shares | 2026-09-23 | |
| Mid ALGERT GLOBAL LLC Registered adviser | $3,557,301 | 0.28% | 235,739 | Shares | 2026-08-13 | |
| Large Public Sector Pension Investment Board Non-US | $3,553,061 | 0.28% | 235,458 | Shares | 2026-08-13 | |
| Mega ROYAL BANK OF CANADA Bank | $3,397,872 | 0.27% | 225,174 | Shares | 2026-08-14 | |
| Large Squarepoint Ops LLC Registered adviser | $3,280,354 | 0.26% | 217,386 | Shares | 2026-08-14 | |
| Mid XTX Topco Ltd | $3,213,807 | 0.25% | 212,976 | Shares | 2026-08-14 | |
| Large Connor, Clark & Lunn Investment Management Ltd. Registered adviser | $2,777,660 | 0.22% | 184,073 | Shares | 2026-08-13 | |
| Large Jefferies Financial Group Inc. Holding company | $2,512,319 | 0.20% | 166,489 | Shares | 2026-08-17 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $2,491,359 | 0.19% | 165,100 | Put | 2026-08-14 | |
| Mega RHUMBLINE ADVISERS Registered adviser | $2,475,559 | 0.19% | 164,053 | Shares | 2026-08-12 | |
| Mid Y-Intercept (Hong Kong) Ltd Exempt adviser | $2,412,477 | 0.19% | 147,914 | Shares | 2026-10-16 | |
| Small Nierenberg Investment Management Company, LLC Registered adviser | $2,397,951 | 0.19% | 158,910 | Shares | 2026-08-11 | |
| Mega Nuveen, LLC | $2,370,125 | 0.18% | 157,066 | Shares | 2026-08-11 | |
| Mega Legal & General Group Plc | $2,350,251 | 0.18% | 155,749 | Shares | 2026-08-14 | |
| Mega UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC Registered adviser | $2,291,368 | 0.18% | 151,847 | Shares | 2026-08-13 | |
| Mega Russell Investments Group, Ltd. | $2,242,127 | 0.17% | 148,584 | Shares | 2026-08-06 | |
| Large Banco Santander, S.A. Bank | $2,221,248 | 0.17% | 147,200 | Shares | 2026-07-29 | |
| Mega VOYA INVESTMENT MANAGEMENT LLC Registered adviser | $2,151,787 | 0.17% | 142,597 | Shares | 2026-08-12 | |
| Mid MIZUHO MARKETS AMERICAS LLC | $2,078,828 | 0.16% | 137,762 | Shares | 2026-07-24 | |
| Mega Swiss National Bank | $2,074,875 | 0.16% | 137,500 | Shares | 2026-08-11 | |
| Large ACADIAN ASSET MANAGEMENT LLC | $2,070,906 | 0.16% | 137,237 | Shares | 2026-08-13 | |
| Large Schonfeld Strategic Advisors LLC Registered adviser | $1,955,166 | 0.15% | 129,567 | Shares | 2026-08-14 | |
| Large FEDERATED HERMES, INC. Adviser | $1,868,428 | 0.15% | 123,819 | Shares | 2026-08-12 | |
| Mega RAYMOND JAMES FINANCIAL INC | $1,841,296 | 0.14% | 122,021 | Shares | 2026-08-14 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $1,779,985 | 0.14% | 117,958 | Shares | 2026-08-14 | |
| Mega AMERIPRISE FINANCIAL INC Adviser | $1,713,046 | 0.13% | 113,522 | Shares | 2026-08-14 | |
| Large BANQUE PICTET & CIE SA | $1,574,143 | 0.12% | 96,514 | Shares | 2026-10-16 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $1,573,887 | 0.12% | 104,300 | Call | 2026-08-14 | |
| Large GABELLI FUNDS LLC Registered adviser | $1,554,270 | 0.12% | 103,000 | Shares | 2026-08-12 | |
| Mega JANE STREET GROUP, LLC | $1,407,897 | 0.11% | 93,300 | Put | 2026-08-14 | |
| Large Trexquant Investment LP Registered adviser | $1,358,975 | 0.11% | 90,058 | Shares | 2026-08-14 | |
| Mega PRICE T ROWE ASSOCIATES INC /MD/ Registered adviser | $1,332,688 | 0.10% | 88,316 | Shares | 2026-08-14 | |
| Mid Cinctive Capital Management LP Registered adviser | $1,311,411 | 0.10% | 86,906 | Shares | 2026-08-14 | |
| Large Universal- Beteiligungs- und Servicegesellschaft mbH | $1,281,201 | 0.10% | 84,904 | Shares | 2026-08-06 | |
| Mid FIDEURAM - INTESA SANPAOLO PRIVATE BANKING S.P.A. | $1,280,567 | 0.10% | 84,862 | Shares | 2026-07-23 | |
| Mega JANE STREET GROUP, LLC | $1,241,907 | 0.10% | 82,300 | Call | 2026-08-14 | |
| Large INTECH INVESTMENT MANAGEMENT LLC Registered adviser | $1,223,361 | 0.10% | 81,071 | Shares | 2026-08-10 | |
| Large NOMURA HOLDINGS INC | $1,207,200 | 0.09% | 80,000 | Call | 2026-08-14 | |
| Large NOMURA HOLDINGS INC | $1,207,200 | 0.09% | 80,000 | Put | 2026-08-14 | |
| Mega CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM Benefit plan | $1,165,355 | 0.09% | 77,227 | Shares | 2026-08-24 | |
| Large Cerity Partners LLC Registered adviser | $1,148,680 | 0.09% | 76,122 | Shares | 2026-08-14 | |
| Mega DEUTSCHE BANK AG\ Non-US | $1,134,088 | 0.09% | 75,155 | Shares | 2026-08-07 |
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