Tandem Diabetes Care
Builds software-updatable insulin pumps, cartridges, and infusion sets for diabetes care.
$21.16
After-hours close−0.27 (−1.26%)
At close$21.43(+0.14%)
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Breakdown13F · Form 4
Institutions 117.44%Insiders 0.96%
A 13F quarter can total more than the shares outstanding — sub-advisers file the same block twice, and a filer's own share count can be a quarter stale. No split is drawn from it.
Shares outstanding 68.53M · Float 62.92M · 91.8% free float
Institutions13F, as of Jun 30, 2026
288 holders · 80.48M shares · 49 new positions · 147 increased · 89 reduced · 49 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| BlackRock, Inc. | 11.58M | 16.90% | +892.3K | Aug 7, 2026 |
| Sessa Capital Im, L.P. | 5.10M | 7.44% | +369.2K | Aug 14, 2026 |
| Vanguard Portfolio Management LLC | 4.30M | 6.27% | +306.3K | Aug 13, 2026 |
| First Light Asset Management, LLC | 3.38M | 4.94% | +2.07M | Aug 14, 2026 |
| Vanguard Capital Management LLC | 3.10M | 4.52% | +57.6K | Aug 13, 2026 |
| State Street Corp | 2.85M | 4.16% | +189.4K | Aug 7, 2026 |
| GW&K Investment Management, LLC | 2.57M | 3.75% | −120.1K | Aug 12, 2026 |
| Jennison Associates LLC | 2.33M | 3.40% | +673.0K | Aug 3, 2026 |
Beneficial owners13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| BlackRock, Inc. | 15.20% | 10.11M | 13G | Apr 29, 2025 ↗ |
| Sessa Capital (Master), L.P. | 6.71% | 4.47M | 13G | May 15, 2025 ↗ |
| Voya Financial, Inc. | 6.30% | 4.34M | 13G | May 5, 2026 ↗ |
| Vanguard Portfolio Management | 5.91% | 4.05M | 13G | Apr 29, 2026 ↗ |
| Vanguard Capital Management | 5.18% | 3.55M | 13G | Apr 30, 2026 ↗ |
InsidersForm 4
| Insider | Role | Shares | % outstanding | Filed |
|---|---|---|---|---|
| John F. Sheridan | director, officer: PRESIDENT & CEO | 160.3K | 0.23% | Aug 18, 2026 |
| Leigh Vosseller | officer: EVP & CHIEF FINANCIAL OFFICER | 77.6K | 0.11% | Aug 18, 2026 |
| Susan Morrison | officer: EVP & Chief Admin. Officer | 52.8K | 0.08% | Aug 18, 2026 |
| Mark David Novara | officer: EVP & CHIEF COMMERCIAL OFFICER | 37.7K | 0.05% | May 19, 2026 |
| Elizabeth Anne Gasser | officer: EVP, Chief Strategy Officer | 34.5K | 0.05% | Aug 18, 2026 |
| Rick Carpenter | officer: EVP & Chief Technology Officer | 32.1K | 0.05% | Aug 18, 2026 |
| Shannon Marie Hansen | officer: EVP & Chief Legal Officer | 31.7K | 0.05% | Aug 18, 2026 |
| Jean-Claude Kyrillos | officer: EVP & Chief Operating Officer | 30.3K | 0.04% | Aug 18, 2026 |
| Peyton R. Howell | director | 29.8K | 0.04% | May 22, 2026 |
| Dick Allen | other: Chair Emeritus | 28.1K | 0.04% | May 22, 2026 |
12 ten-percent owners hold 1.48M shares by Form 4, outside the officers-and-directors figure above · 23 people have not refiled in the last 18 months (440.8K shares), so they are not in the figure above
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Mar 17, 2026 | Mark David Novaraofficer: EVP & CHIEF COMMERCIAL OFFICER | Sale | 187 | $23.05 | 37,656 |
| Mar 5, 2026 | Mark David Novaraofficer: EVP & CHIEF COMMERCIAL OFFICER | Sale | 2 | $22.81 | 35,969 |
CongressHouse and Senate disclosures
Not reported.