TNDMNasdaqSurgical & Medical Instruments & ApparatusFiscal year ends December 31
TANDEM DIABETES CARE INC
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Aug 6, 2026
$16.38+0.14 (+0.86%)
Close on Oct 19, 2026
- Market cap
- $1.13B
- P/E (TTM)
- –
- Dividend yield
- –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
100.0%
79M of 70M shares
Institutional holders
274
49 new, 44 sold out
Net institutional buying
0M
In Q2 2026
Insider trades, 12 months
0 buys · 2 sales
Net sold $4.36K
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| Sessa Capital IM, L.P. | 4,466,307 | 6.71% | 13G (passive) | Mar 31, 2025 |
| Vanguard Portfolio Management | 4,052,274 | 5.91% | 13G (passive) | Mar 31, 2026 |
| Vanguard Capital Management | 3,553,772 | 5.18% | 13G (passive) | Mar 31, 2026 |
| Capital World Investors | 3,265,300 | 5.00% | 13G (passive) amendment | Aug 30, 2024 |
| BlackRock, Inc. | 10,106,682 | 15.20% | 13G (passive) amendment | Mar 31, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of TNDM | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| BlackRock, Inc. | 11,583,125 | 16.65% | $174.79M | +892,281 | 0.00% |
| Sessa Capital IM, L.P. | 5,100,000 | 7.33% | $76.96M | +369,243 | 1.29% |
| Vanguard Portfolio Management LLC | 4,299,667 | 6.18% | $64.88M | +306,334 | 0.00% |
| First Light Asset Management, LLC | 3,383,553 | 4.86% | $51.06M | +2,068,838 | 3.10% |
| Vanguard Capital Management LLC | 3,096,536 | 4.45% | $46.73M | +57,617 | 0.00% |
| State Street Corp | 2,851,646 | 4.10% | $43.03M | +189,386 | 0.00% |
| GW&K Investment Management, LLC | 2,569,032 | 3.69% | $38.77K | −120,074 | 0.30% |
| Jennison Associates LLC | 2,331,429 | 3.35% | $35.18M | +672,981 | 0.02% |
| Paradice Investment Management LLC | 2,024,014 | 2.91% | $30.54M | −18,411 | 4.87% |
| Jacobs Levy Equity Management, Inc | 2,006,429 | 2.88% | $30.28M | +482,483 | 0.11% |
| Freestone Grove Partners LP | 1,866,134 | 2.68% | $28.16M | +535,392 | 0.18% |
| Geode Capital Management, LLC | 1,800,797 | 2.59% | $27.18M | +120,934 | 0.00% |
| Driehaus Capital Management LLC | 1,786,996 | 2.57% | $26.97M | −517,418 | 0.16% |
| Citadel Advisors LLC | 1,735,879 | 2.49% | $26.19M | −456,788 | 0.00% |
| Millennium Management LLC | 1,311,739 | 1.89% | $19.79M | +550,067 | 0.01% |
| Woodline Partners LP | 1,307,439 | 1.88% | $19.73M | New | 0.06% |
| ArrowMark Colorado Holdings LLC | 1,299,586 | 1.87% | $19.61M | −1,804,023 | 0.82% |
| UBS Group AG | 1,146,580 | 1.65% | $17.30M | −901,221 | 0.00% |
| FMR LLC | 976,432 | 1.40% | $14.73M | +262,421 | 0.00% |
| Royce & Associates LP | 900,590 | 1.29% | $13.59M | +204,000 | 0.11% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 274 | 79M | 100.0% | 49 / 95 | 91 / 44 | 15M | 15M |
| Q1 2026 | 273 | 79M | 100.0% | 45 / 94 | 94 / 35 | 20M | 9M |
| Q4 2025 | 268 | 75M | 100.0% | 52 / 85 | 99 / 32 | 13M | 13M |
| Q3 2025 | 255 | 75M | 100.0% | 43 / 75 | 97 / 57 | 11M | 17M |
| Q2 2025 | 270 | 82M | 100.0% | 40 / 116 | 71 / 43 | 15M | 7M |
| Q1 2025 | 275 | 73M | 100.0% | 40 / 107 | 85 / 77 | 14M | 12M |
| Q4 2024 | 315 | 72M | 100.0% | 42 / 137 | 91 / 52 | 12M | 13M |
| Q3 2024 | 331 | 73M | 100.0% | 59 / 109 | 117 / 41 | 20M | 9M |
| Q2 2024 | 316 | 74M | 100.0% | 63 / 124 | 91 / 35 | 11M | 14M |
| Q1 2024 | 291 | 77M | 100.0% | 54 / 123 | 78 / 29 | 19M | 14M |
| Q4 2023 | 268 | 72M | 100.0% | 75 / 85 | 85 / 32 | 10M | 8M |
| Q3 2023 | 226 | 70M | 100.0% | 26 / 80 | 90 / 45 | 11M | 9M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
| Fund | Shares | % of TNDM | Value | % of fund | As of |
|---|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 4,129,585 | 5.94% | $62.32M | 0.06% | Jun 30, 2026 |
| Vanguard Total Stock Market Index Fund | 2,186,918 | 3.14% | $33.00M | 0.00% | Jun 30, 2026 |
| iShares Russell 2000 ETF | 1,818,684 | 2.61% | $27.44M | 0.03% | Jun 30, 2026 |
| Vanguard Small-Cap Index Fund | 1,570,019 | 2.26% | $23.69M | 0.01% | Jun 30, 2026 |
| Vanguard Small-Cap Growth Index Fund | 901,467 | 1.30% | $13.60M | 0.03% | Jun 30, 2026 |
| Vanguard Extended Market Index Fund | 788,509 | 1.13% | $11.90M | 0.01% | Jun 30, 2026 |
| Fidelity Small Cap Index Fund | 763,465 | 1.10% | $14.89M | 0.04% | Jul 31, 2026 |
| PGIM Jennison Health Sciences Fund | 680,031 | 0.98% | $11.70M | 0.84% | May 29, 2026 |
| iShares Russell 2000 Growth ETF | 644,820 | 0.93% | $9.73M | 0.06% | Jun 30, 2026 |
| State Street(R) SPDR(R) Portfolio S&P 600(TM) Small Cap ETF | 627,958 | 0.90% | $9.48M | 0.06% | Jun 30, 2026 |
| Meridian Growth Fund | 483,102 | 0.69% | $7.29M | 1.34% | Jun 30, 2026 |
| Strategic Advisers Fidelity U.S. Total Stock Fund | 476,900 | 0.69% | $8.20M | 0.00% | May 31, 2026 |
| Vanguard Tax-Managed Small-Cap Fund | 454,971 | 0.65% | $6.87M | 0.06% | Jun 30, 2026 |
| Royce Small-Cap Opportunity Fund | 423,694 | 0.61% | $6.39M | 0.45% | Jun 30, 2026 |
| Fidelity Enhanced Small Cap Core ETF | 360,810 | 0.52% | $5.44M | 0.09% | Jun 30, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| John F. Sheridan | PRESIDENT & CEO, Director | 158,425 | 0.23% | Aug 18, 2026 |
| Rick Carpenter | EVP & Chief Technology Officer | 32,968 | 0.05% | Aug 18, 2026 |
| Jean-Claude Kyrillos | EVP & Chief Operating Officer | 30,290 | 0.04% | Aug 18, 2026 |
| Susan Morrison | EVP & Chief Admin. Officer | 52,788 | 0.08% | Aug 18, 2026 |
| Elizabeth Anne Gasser | EVP, Chief Strategy Officer | 35,534 | 0.05% | Aug 18, 2026 |
| Leigh Vosseller | EVP & CHIEF FINANCIAL OFFICER | 76,475 | 0.11% | Aug 18, 2026 |
| Shannon Marie Hansen | EVP & Chief Legal Officer | 33,203 | 0.05% | Aug 18, 2026 |
| Mark David Novara | EVP & CHIEF COMMERCIAL OFFICER | 37,732 | 0.05% | May 19, 2026 |
| Rebecca B. Robertson | Director | 22,542 | 0.03% | May 22, 2026 |
| Peyton R. Howell | Director | 29,836 | 0.04% | May 22, 2026 |
| Joao Paulo Falcao Malagueira | Director | 22,458 | 0.03% | May 22, 2026 |
| Sandra Beaver | Director | 0 | – | May 22, 2026 |
| Christopher J. Twomey | Director | 37,114 | 0.05% | May 22, 2026 |
| Rajwant Sodhi | Director | 24,280 | 0.03% | May 22, 2026 |
| Kathleen McGroddy-Goetz | Director | 26,612 | 0.04% | May 22, 2026 |
| Myoungil Cha | Director | 22,458 | 0.03% | May 22, 2026 |
| Kim D. Blickenstaff | Director | 183,038 | 0.26% | Nov 22, 2024 |
| Dick Allen | – | 50,903 | 0.07% | May 22, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | Aug 15, 2026 | Option exercise | +1,496 | – | – | 50,895 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | Aug 15, 2026 | Tax withholding | −537 | $22.72 | $12.20K | 50,358 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | Aug 15, 2026 | Option exercise | +2,624 | – | – | 52,982 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | Aug 15, 2026 | Tax withholding | −942 | $22.72 | $21.40K | 52,040 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Aug 15, 2026 | Option exercise | +1,917 | – | – | 2,425 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Aug 15, 2026 | Tax withholding | −589 | $22.72 | $13.38K | 508 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Aug 15, 2026 | Option exercise | +1,097 | – | – | 1,097 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Aug 15, 2026 | Tax withholding | −1,029 | $22.72 | $23.38K | 1,396 |
| Susan Morrison EVP & Chief Admin. Officer | Aug 15, 2026 | Tax withholding | −495 | $22.72 | $11.25K | 52,788 |
| Susan Morrison EVP & Chief Admin. Officer | Aug 15, 2026 | Option exercise | +1,730 | – | – | 53,283 |
| Susan Morrison EVP & Chief Admin. Officer | Aug 15, 2026 | Option exercise | +1,097 | – | – | 51,867 |
| Susan Morrison EVP & Chief Admin. Officer | Aug 15, 2026 | Tax withholding | −314 | $22.72 | $7.13K | 51,553 |
| Shannon Marie Hansen EVP & Chief Legal Officer | Aug 15, 2026 | Option exercise | +1,097 | – | – | 31,268 |
| Shannon Marie Hansen EVP & Chief Legal Officer | Aug 15, 2026 | Tax withholding | −559 | $22.72 | $12.70K | 30,709 |
| Shannon Marie Hansen EVP & Chief Legal Officer | Aug 15, 2026 | Option exercise | +1,917 | – | – | 32,626 |
| Shannon Marie Hansen EVP & Chief Legal Officer | Aug 15, 2026 | Tax withholding | −976 | $22.72 | $22.17K | 31,650 |
| John F. Sheridan PRESIDENT & CEO, Director | Aug 15, 2026 | Option exercise | +5,982 | – | – | 158,425 |
| John F. Sheridan PRESIDENT & CEO, Director | Aug 15, 2026 | Tax withholding | −3,044 | $22.72 | $69.16K | 155,381 |
| John F. Sheridan PRESIDENT & CEO, Director | Aug 15, 2026 | Option exercise | +9,934 | – | – | 165,315 |
| John F. Sheridan PRESIDENT & CEO, Director | Aug 15, 2026 | Tax withholding | −5,055 | $22.72 | $114.85K | 160,260 |
| Rick Carpenter EVP & Chief Technology Officer | Aug 15, 2026 | Option exercise | +1,610 | – | – | 32,968 |
| Rick Carpenter EVP & Chief Technology Officer | Aug 15, 2026 | Tax withholding | −457 | $22.72 | $10.38K | 31,358 |
| Rick Carpenter EVP & Chief Technology Officer | Aug 15, 2026 | Option exercise | +897 | – | – | 31,815 |
| Rick Carpenter EVP & Chief Technology Officer | Aug 15, 2026 | Tax withholding | −820 | $22.72 | $18.63K | 32,148 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | Aug 15, 2026 | Tax withholding | −535 | $22.72 | $12.16K | 30,290 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | Aug 15, 2026 | Option exercise | +1,010 | – | – | 30,825 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | Jul 15, 2026 | Tax withholding | −1,926 | $15.28 | $29.43K | 29,815 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | Jul 15, 2026 | Option exercise | +3,636 | – | – | 31,741 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Jun 2, 2026 | Gift | +7,160 | – | – | 33,109 |
| Elizabeth Anne Gasser EVP, Chief Strategy Officer | Jun 2, 2026 | Gift | −7,160 | – | – | 0 |
| Peyton R. Howell Director | May 21, 2026 | Option exercise | +8,759 | – | – | 29,836 |
| Kathleen McGroddy-Goetz Director | May 21, 2026 | Option exercise | +8,759 | – | – | 26,612 |
| Rebecca B. Robertson Director | May 21, 2026 | Option exercise | +8,759 | – | – | 22,542 |
| Joao Paulo Falcao Malagueira Director | May 21, 2026 | Option exercise | +8,759 | – | – | 22,458 |
| Myoungil Cha Director | May 21, 2026 | Option exercise | +8,759 | – | – | 22,458 |
| Christopher J. Twomey Director | May 21, 2026 | Option exercise | +8,759 | – | – | 24,434 |
| Rajwant Sodhi Director | May 21, 2026 | Option exercise | +8,759 | – | – | 24,280 |
| Dick Allen – | May 21, 2026 | Option exercise | +8,759 | – | – | 28,146 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | May 15, 2026 | Tax withholding | −2,139 | $12.82 | $27.42K | 27,671 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | May 15, 2026 | Option exercise | +4,038 | – | – | 29,810 |
| Jean-Claude Kyrillos EVP & Chief Operating Officer | May 15, 2026 | Award | +434 | $10.90 | $4.73K | 28,105 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Tax withholding | −314 | $12.82 | $4.03K | 44,491 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Option exercise | +1,097 | – | – | 44,805 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Option exercise | +1,503 | – | – | 44,138 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Option exercise | +6,923 | – | – | 51,414 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Tax withholding | −1,980 | $12.82 | $25.38K | 49,434 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Award | +1,336 | $10.90 | $14.56K | 50,770 |
| Susan Morrison EVP & Chief Admin. Officer | May 15, 2026 | Tax withholding | −430 | $12.82 | $5.51K | 43,708 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Option exercise | +7,667 | – | – | 32,186 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Option exercise | +1,437 | – | – | 24,713 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Tax withholding | −732 | $12.82 | $9.38K | 23,981 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Award | +1,886 | $10.90 | $20.56K | 30,171 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Tax withholding | −3,901 | $12.82 | $50.01K | 28,285 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Tax withholding | −559 | $12.82 | $7.17K | 24,519 |
| Shannon Marie Hansen EVP & Chief Legal Officer | May 15, 2026 | Option exercise | +1,097 | – | – | 25,078 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | May 15, 2026 | Tax withholding | −3,766 | $12.82 | $48.28K | 48,063 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | May 15, 2026 | Option exercise | +1,503 | – | – | 40,914 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | May 15, 2026 | Tax withholding | −540 | $12.82 | $6.92K | 40,374 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | May 15, 2026 | Option exercise | +1,496 | – | – | 41,870 |
| Leigh Vosseller EVP & CHIEF FINANCIAL OFFICER | May 15, 2026 | Tax withholding | −537 | $12.82 | $6.88K | 41,333 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Planned insider sales
Notices of proposed sale filed on Form 144 before shares are sold
| Seller | Filed | Shares | Market value | Planned sale | Acquired through |
|---|---|---|---|---|---|
| Novara Mark Officer | Sep 17, 2026 | 360 | $6.31K | Sep 17, 2026 | Restricted Stock Units |
| Novara Mark Officer | Aug 18, 2026 | 131 | $2.92K | Aug 18, 2026 | Restricted Stock Units |
| Novara Mark Officer | Jun 17, 2026 | 361 | $6.03K | Jun 17, 2026 | Restricted Stock Units |
| Novara Mark Officer | May 19, 2026 | 266 | $3.60K | May 19, 2026 | Restricted Stock Units |
| Novara Mark Officer | Mar 17, 2026 | 187 | $4.10K | Mar 17, 2026 | Restricted Stock Units |
| Novara Mark Officer | Mar 5, 2026 | 2 | $47 | Mar 5, 2026 | Restricted Stock Units |
| Kim D. Blickenstaff Board of Directors, Chair Emeritus | Nov 21, 2024 | 30,000 | $900.00K | Nov 21, 2024 | Purchase |
| Kim D. Blickenstaff Board of Directors Chair Emeritus | Nov 20, 2024 | 10,000 | $1.20M | Nov 20, 2024 | PURCHASE |