🕵️ Tandem Diabetes Care, Inc. ($TNDM)
SEC insider & ownership activity, last 12 months · CIK 1438133 · every row links its SEC filing
Over the last 12 months insiders sold $4K against $252K of open-market buying. Vosseller Leigh bought $149K in discretionary trades (Aug). 2 planned sales are pending, the largest $6K (Mark Novara). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
2 buyers, $252K (2 lots) · 1 seller, $4K (2 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Vosseller Leigh | 1 | $149K | 0 | – | Aug 8, 2025 |
| John F. Sheridan | 1 | $102K | 0 | – | Aug 11, 2025 |
| Mark Novara | 0 | – | 2 | $4K | Mar 17, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Blackrock, Inc. | 15.2% | 13G | Apr 29, 2025 | filing ↗ | |
| Sessa Capital (MASTER), L.P. | 6.7% | 13G | May 15, 2025 | filing ↗ | |
| Sessa Capital GP, LLC | 6.7% | 13G | May 15, 2025 | filing ↗ | |
| Sessa Capital IM, L.P. | 6.7% | 13G | May 15, 2025 | filing ↗ | |
| Sessa Capital IM GP, LLC | 6.7% | 13G | May 15, 2025 | filing ↗ | |
| John Petry | 6.7% | 13G | May 15, 2025 | filing ↗ | |
| VOYA Financial, Inc. | 6.3% | 13G | May 5, 2026 | filing ↗ | |
| Vanguard Portfolio Management | 5.9% | 13G | Apr 29, 2026 | filing ↗ | |
| Vanguard Capital Management | 5.2% | 13G | Apr 30, 2026 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Mark Novara | $6K | Jun 17, 2026 | filing ↗ |
| Mark Novara | $4K | May 19, 2026 | filing ↗ |
| Mark Novara | $4K | Mar 17, 2026 | filing ↗ |
| Mark Novara | $47 | Mar 5, 2026 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Material Modifications to Rights of Security Holders (3.03) | May 20, 2026 | filing ↗ |
| Officer/director changes (5.02) | May 20, 2026 | filing ↗ |
| Shareholder vote (5.07) | May 20, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 20, 2026 | filing ↗ |
| Officer/director changes (5.02) | May 11, 2026 | filing ↗ |
| Earnings (2.02) | May 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 7, 2026 | filing ↗ |
| Material agreement (1.01) | Feb 23, 2026 | filing ↗ |
| New financial obligation (2.03) | Feb 23, 2026 | filing ↗ |
| Unregistered equity sale (3.02) | Feb 23, 2026 | filing ↗ |
| Other events (8.01) | Feb 23, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 23, 2026 | filing ↗ |
| Earnings (2.02) | Feb 19, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 19, 2026 | filing ↗ |
| Charter/bylaw changes (5.03) | Dec 26, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Dec 26, 2025 | filing ↗ |
| Officer/director changes (5.02) | Nov 7, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 7, 2025 | filing ↗ |
| Earnings (2.02) | Nov 6, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 6, 2025 | filing ↗ |
| Other events (8.01) | Aug 6, 2025 | filing ↗ |
| Earnings (2.02) | Aug 6, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 6, 2025 | filing ↗ |