TANDEM DIABETES CARE INC (TNDM) Top 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 March 31, 2026. The institutional investors covered on this page collectively reported approximately $1.43B 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 $204.94M in its March 31, 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 $164.64M, representing an estimated loss of -19.67% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 49% 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
270
Total Reported Value
$1.43B
Largest Holder
Blackrock, Inc.
Largest Position
$204.94M
Insider Transactions (90d)
0
Latest Filing Quarter
Q1 2026
New Institutional Positions
111
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% | 10,690,844 | $204,943,480 | $164,638,998 | -$40,304,482 | -19.67% | |
| Sessa Capital Im, L.P. | 1.73% | 4,730,757 | $90,688,612 | $72,853,658 | -$17,834,954 | -19.67% | |
| Vanguard Portfolio Management Llc | 0.00% | 3,993,333 | $76,552,194 | $61,497,328 | -$15,054,866 | -19.67% | |
| Arrowmark Colorado Holdings Llc | 1.58% | 3,103,609 | $59,496,185 | $47,795,579 | -$11,700,606 | -19.67% | |
| Vanguard Capital Management Llc | 0.00% | 3,038,919 | $58,256,077 | $46,799,353 | -$11,456,724 | -19.67% | |
| State Street Corp | 0.00% | 2,662,260 | $51,035,524 | $40,998,804 | -$10,036,720 | -19.67% | |
| Driehaus Capital Management Llc | 0.32% | 2,304,414 | $44,175,616 | $35,487,976 | -$8,687,640 | -19.67% | |
| Goldman Sachs Group Inc | 0.01% | 2,218,922 | $42,536,734 | $34,171,399 | -$8,365,335 | -19.67% | |
| Citadel Advisors Llc | 0.03% | 2,192,667 | $42,033,426 | $33,767,072 | -$8,266,354 | -19.67% | |
| Ubs Group Ag | 0.01% | 2,047,801 | $39,256,344 | $31,536,135 | -$7,720,209 | -19.67% | |
| Paradice Investment Management Llc | 7.35% | 2,042,425 | $39,153,287 | $31,453,345 | -$7,699,942 | -19.67% | |
| Two Sigma Investments, Lp | 0.03% | 1,864,194 | $35,736,599 | $28,708,588 | -$7,028,011 | -19.67% | |
| Geode Capital Management, Llc | 0.00% | 1,679,863 | $32,209,339 | $25,869,890 | -$6,339,449 | -19.68% | |
| Jennison Associates Llc | 0.02% | 1,658,448 | $31,792,448 | $25,540,099 | -$6,252,349 | -19.67% | |
| Jacobs Levy Equity Management, Inc | 0.12% | 1,523,946 | $29,214,045 | $23,468,768 | -$5,745,277 | -19.67% | |
| Marshall Wace, Llp | 0.03% | 1,442,472 | $27,652,189 | $22,214,069 | -$5,438,120 | -19.67% | |
| Morgan Stanley | 0.00% | 1,357,542 | $26,024,095 | $20,906,147 | -$5,117,948 | -19.67% | |
| Freestone Grove Partners Lp | 0.18% | 1,330,742 | $25,510,324 | $20,493,427 | -$5,016,897 | -19.67% | |
| First Light Asset Management, Llc | 2.26% | 1,314,715 | $25,203,087 | $20,246,611 | -$4,956,476 | -19.67% | |
| Baillie Gifford & Co | 0.02% | 1,089,393 | $20,883,664 | $16,776,652 | -$4,107,012 | -19.67% | |
| Wellington Management Group Llp | 0.00% | 1,042,764 | $19,989,786 | $16,058,566 | -$3,931,220 | -19.67% | |
| Voya Investment Management Llc | 0.02% | 804,137 | $15,415,306 | $12,383,710 | -$3,031,596 | -19.67% | |
| D. E. Shaw & Co., Inc. | 0.01% | 783,906 | $15,027,478 | $12,072,152 | -$2,955,326 | -19.67% | |
| Soleus Capital Management, L.P. | 0.61% | 783,000 | $15,010,110 | $12,058,200 | -$2,951,910 | -19.67% | |
| Defilade Capital Management, L.P. | 2.05% | 761,905 | $14,605,719 | $11,733,337 | -$2,872,382 | -19.67% | |
| Millennium Management Llc | 0.01% | 761,672 | $14,601,252 | $11,729,749 | -$2,871,503 | -19.67% | |
| Fmr Llc | 0.00% | 714,011 | $13,687,586 | $10,995,769 | -$2,691,817 | -19.67% | |
| Northern Trust Corp | 0.00% | 706,609 | $13,545,694 | $10,881,779 | -$2,663,915 | -19.67% | |
| Royce & Associates Lp | 0.13% | 696,590 | $13,353,630 | $10,727,486 | -$2,626,144 | -19.67% | |
| Quantinno Capital Management Lp | 0.02% | 653,870 | $12,534,688 | $10,069,598 | -$2,465,090 | -19.67% | |
| Charles Schwab Investment Management Inc | 0.00% | 642,598 | $12,318,604 | $9,896,009 | -$2,422,595 | -19.67% | |
| Exoduspoint Capital Management, Lp | 0.12% | 632,899 | $12,132,674 | $9,746,645 | -$2,386,029 | -19.67% | |
| Holocene Advisors, Lp | 0.02% | 477,359 | $9,150,972 | $7,351,329 | -$1,799,643 | -19.67% | |
| Vanguard Fiduciary Trust Co | 0.00% | 471,658 | $9,041,684 | $7,263,533 | -$1,778,151 | -19.67% | |
| Aberdeen Group Plc | 0.01% | 434,027 | $8,320,298 | $6,684,016 | -$1,636,282 | -19.67% | |
| Barclays Plc | 0.00% | 421,236 | $8,075,093 | $6,487,034 | -$1,588,059 | -19.67% | |
| Point72 Asset Management, L.P. | 0.01% | 420,478 | $8,060,563 | $6,475,361 | -$1,585,202 | -19.67% | |
| Frontier Capital Management Co Llc | 0.08% | 397,209 | $7,614,498 | $6,117,019 | -$1,497,479 | -19.67% | |
| Bank Of America Corp | 0.00% | 373,224 | $7,154,705 | $5,747,650 | -$1,407,055 | -19.67% | |
| Nuveen, Llc | 0.00% | 363,802 | $6,974,085 | $5,602,551 | -$1,371,534 | -19.67% | |
| Dafna Capital Management Llc | 1.55% | 355,208 | $6,809,337 | $5,470,203 | -$1,339,134 | -19.67% | |
| First Trust Advisors Lp | 0.00% | 342,707 | $6,569,693 | $5,277,688 | -$1,292,005 | -19.67% | |
| Bank Of New York Mellon Corp | 0.00% | 336,291 | $6,446,701 | $5,178,881 | -$1,267,820 | -19.67% | |
| Aqr Capital Management Llc | 0.00% | 331,916 | $6,362,830 | $5,111,506 | -$1,251,324 | -19.67% | |
| Principal Financial Group Inc | 0.00% | 331,541 | $6,355,640 | $5,105,731 | -$1,249,909 | -19.67% | |
| Invesco Ltd. | 0.00% | 294,052 | $5,636,977 | $4,528,401 | -$1,108,576 | -19.67% | |
| Sector Gamma As | 1.21% | 267,091 | $5,120,134 | $4,113,201 | -$1,006,933 | -19.67% | |
| Edmond De Rothschild Holding S.A. | 0.07% | 258,200 | $4,949,694 | $3,976,280 | -$973,414 | -19.67% | |
| Beaconlight Capital, Llc | 2.74% | 253,877 | $4,866,822 | $3,909,706 | -$957,116 | -19.67% | |
| Trexquant Investment Lp | 0.03% | 249,298 | $4,779,043 | $3,839,189 | -$939,854 | -19.67% |
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.