TANDEM DIABETES CARE INC (TNDM) Institutional Shareholders
TANDEM DIABETES CARE INC (TNDM) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $1.19B in TNDM holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of TNDM tracked by InsiderSet, reporting ownership valued at approximately $174.79M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $195.41M, representing an estimated gain of +11.80% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 50% of the total disclosed TNDM value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Sessa Capital Im, L.P., Vanguard Portfolio Management Llc, and several other long-term asset managers with concentrated positions in TANDEM DIABETES CARE INC (TNDM).
This page ranks the largest institutional TNDM shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
264
Total Reported Value
$1.19B
Largest Holder
Blackrock, Inc.
Largest Position
$174.79M
Insider Transactions (90d)
28
Latest Filing Quarter
Q2 2026
New Institutional Positions
55
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.00% | 11,583,125 | $174,789,356 | $195,407,319 | +$20,617,963 | +11.80% | |
| Sessa Capital Im, L.P. | 1.33% | 5,100,000 | $76,959,000 | $86,037,000 | +$9,078,000 | +11.80% | |
| Vanguard Portfolio Management Llc | 0.00% | 4,299,667 | $64,881,975 | $72,535,382 | +$7,653,407 | +11.80% | |
| First Light Asset Management, Llc | 3.10% | 3,383,553 | $51,057,815 | $57,080,539 | +$6,022,724 | +11.80% | |
| Vanguard Capital Management Llc | 0.00% | 3,096,536 | $46,726,728 | $52,238,562 | +$5,511,834 | +11.80% | |
| State Street Corp | 0.00% | 2,851,646 | $43,031,338 | $48,107,268 | +$5,075,930 | +11.80% | |
| Gw&K Investment Management, Llc | 0.30% | 2,569,032 | $38,767,000 | $43,339,570 | +$4,572,570 | +11.80% | |
| Jennison Associates Llc | 0.02% | 2,331,429 | $35,181,264 | $39,331,207 | +$4,149,943 | +11.80% | |
| Paradice Investment Management Llc | 4.87% | 2,024,014 | $30,542,371 | $34,145,116 | +$3,602,745 | +11.80% | |
| Jacobs Levy Equity Management, Inc | 0.11% | 2,006,429 | $30,277,014 | $33,848,457 | +$3,571,443 | +11.80% | |
| Freestone Grove Partners Lp | 0.18% | 1,866,134 | $28,159,962 | $31,481,681 | +$3,321,719 | +11.80% | |
| Geode Capital Management, Llc | 0.00% | 1,800,797 | $27,179,463 | $30,379,445 | +$3,199,982 | +11.77% | |
| Driehaus Capital Management Llc | 0.16% | 1,786,996 | $26,965,770 | $30,146,623 | +$3,180,853 | +11.80% | |
| Citadel Advisors Llc | 0.02% | 1,735,879 | $26,194,414 | $29,284,279 | +$3,089,865 | +11.80% | |
| Millennium Management Llc | 0.01% | 1,311,739 | $19,794,142 | $22,129,037 | +$2,334,895 | +11.80% | |
| Woodline Partners Lp | 0.06% | 1,307,439 | $19,729,255 | $22,056,496 | +$2,327,241 | +11.80% | |
| Arrowmark Colorado Holdings Llc | 0.82% | 1,299,586 | $19,610,753 | $21,924,016 | +$2,313,263 | +11.80% | |
| Ubs Group Ag | 0.00% | 1,146,580 | $17,301,892 | $19,342,805 | +$2,040,913 | +11.80% | |
| Fmr Llc | 0.00% | 976,432 | $14,734,363 | $16,472,408 | +$1,738,045 | +11.80% | |
| Royce & Associates Lp | 0.11% | 900,590 | $13,589,903 | $15,192,953 | +$1,603,050 | +11.80% | |
| Wellington Management Group Llp | 0.00% | 871,811 | $13,155,629 | $14,707,452 | +$1,551,823 | +11.80% | |
| Goldman Sachs Group Inc | 0.00% | 862,301 | $13,012,122 | $14,547,018 | +$1,534,896 | +11.80% | |
| Northern Trust Corp | 0.00% | 753,690 | $11,373,182 | $12,714,750 | +$1,341,568 | +11.80% | |
| Verition Fund Management Llc | 0.07% | 700,000 | $10,563,000 | $11,809,000 | +$1,246,000 | +11.80% | |
| Exoduspoint Capital Management, Lp | 0.10% | 691,789 | $10,439,096 | $11,670,480 | +$1,231,384 | +11.80% | |
| Qube Research & Technologies Ltd | 0.01% | 683,823 | $10,318,889 | $11,536,094 | +$1,217,205 | +11.80% | |
| D. E. Shaw & Co., Inc. | 0.01% | 681,808 | $10,288,482 | $11,502,101 | +$1,213,619 | +11.80% | |
| Arrowstreet Capital, Limited Partnership | 0.00% | 667,689 | $10,075,427 | $11,263,913 | +$1,188,486 | +11.80% | |
| Charles Schwab Investment Management Inc | 0.00% | 656,836 | $9,911,655 | $11,080,823 | +$1,169,168 | +11.80% | |
| Morgan Stanley | 0.00% | 647,069 | $9,764,284 | $10,916,054 | +$1,151,770 | +11.80% | |
| Point72 Asset Management, L.P. | 0.01% | 610,903 | $9,218,526 | $10,305,934 | +$1,087,408 | +11.80% | |
| Soleus Capital Management, L.P. | 0.30% | 575,000 | $8,676,750 | $9,700,250 | +$1,023,500 | +11.80% | |
| Bank Of Montreal | 0.00% | 564,966 | $8,525,337 | $9,530,976 | +$1,005,639 | +11.80% | |
| Two Sigma Investments, Lp | 0.01% | 558,409 | $8,426,392 | $9,420,360 | +$993,968 | +11.80% | |
| Aqr Capital Management Llc | 0.00% | 533,837 | $8,055,599 | $9,005,830 | +$950,231 | +11.80% | |
| Vanguard Fiduciary Trust Co | 0.00% | 491,103 | $7,410,744 | $8,284,908 | +$874,164 | +11.80% | |
| Aberdeen Group Plc | 0.01% | 441,738 | $6,665,826 | $7,452,120 | +$786,294 | +11.80% | |
| Jump Financial, Llc | 0.05% | 404,400 | $6,102,396 | $6,822,228 | +$719,832 | +11.80% | |
| Bank Of America Corp | 0.00% | 395,054 | $5,961,365 | $6,664,561 | +$703,196 | +11.80% | |
| Frontier Capital Management Co Llc | 0.05% | 380,458 | $5,741,106 | $6,418,326 | +$677,220 | +11.80% | |
| Jpmorgan Chase & Co | 0.00% | 349,652 | $5,534,991 | $5,898,629 | +$363,638 | +6.57% | |
| Tudor Investment Corp Et Al | 0.02% | 362,708 | $5,473,264 | $6,118,884 | +$645,620 | +11.80% | |
| Dafna Capital Management Llc | 1.02% | 355,208 | $5,360,089 | $5,992,359 | +$632,270 | +11.80% | |
| Bank Of New York Mellon Corp | 0.00% | 352,161 | $5,314,107 | $5,940,956 | +$626,849 | +11.80% | |
| Barclays Plc | 0.00% | 350,429 | $5,287,972 | $5,911,737 | +$623,765 | +11.80% | |
| Principal Financial Group Inc | 0.00% | 335,094 | $5,056,568 | $5,653,036 | +$596,468 | +11.80% | |
| Invesco Ltd. | 0.00% | 321,128 | $4,845,821 | $5,417,429 | +$571,608 | +11.80% | |
| Y-Intercept (Hong Kong) Ltd | 0.09% | 314,653 | $4,748,114 | $5,308,196 | +$560,082 | +11.80% | |
| Alberta Investment Management Corp | 0.03% | 313,700 | $4,733,733 | $5,292,119 | +$558,386 | +11.80% | |
| Edmond De Rothschild Holding S.A. | 0.06% | 308,200 | $4,650,738 | $5,199,334 | +$548,596 | +11.80% |
Frequently asked questions about TNDM
Who owns the most TNDM stock?
The largest holders of TNDM are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for TANDEM DIABETES CARE INC (TNDM).
Is TNDM widely held by superinvestors?
Many widely followed stocks like TNDM appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly TNDM is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.