TNDM · Insider trading · 13F holders · Congress trades
Tandem Diabetes Care Inc (TNDM)
Who is buying and selling TNDM: company insiders on SEC Form 4, hedge funds and superinvestors on Form 13F, and members of Congress under the STOCK Act. Every figure links to the filing or page it comes from.
- 13F filers holding
- 9
- Insider buys, 90 days
- $0
- Insider sales, 90 days
- $33K
- Congress trades, 12 months
- 3
TNDM at a glance
- Between Aug 1, 2026 and Oct 29, 2026, 1 TNDM insider filed 1 sale worth $33K on SEC Form 4, and no open-market purchases; 1 of the sales were pre-planned under Rule 10b5-1.
- 9 13F filers hold TNDM among their 50 largest positions, worth $200.7M combined. The biggest bets by portfolio weight are Paradice Investment Management LLC (5.5%), KVP Capital Advisors, LP (3.3%) and First Light Asset Management, LLC (3.1%). In their latest 13Fs, 1 manager opened a new position and 3 added to one.
- Members of Congress have disclosed 8 TNDM trades since 2015, 3 purchases and 0 sales in the past year; the latest was Gilbert Ray Cisneros, Jr. (D-CA), buying $1K–15K on Sep 29, 2026.
- TNDM last closed at $19.79 on Oct 29, 2026.
TNDM insider trading
Between Aug 1, 2026 and Oct 29, 2026, 1 TNDM insider filed 1 sale worth $33K on SEC Form 4, and no open-market purchases; 1 of the sales were pre-planned under Rule 10b5-1.
| Filed | Insider | Role | Trade | Shares | Price | Value | Form 4 |
|---|---|---|---|---|---|---|---|
| Oct 29, 2026 | Twomey Christopher J | Director | Sale10b5-1 | 1,700 | $19.15 | $33K | SEC |
Who owns TNDM? Hedge funds and superinvestors
9 13F filers hold TNDM among their 50 largest positions, worth $200.7M combined. The biggest bets by portfolio weight are Paradice Investment Management LLC (5.5%), KVP Capital Advisors, LP (3.3%) and First Light Asset Management, LLC (3.1%). In their latest 13Fs, 1 manager opened a new position and 3 added to one.
| Manager | % of portfolio | Value | Shares | Last quarter | 13F |
|---|---|---|---|---|---|
| Sessa Capital IM, L.P.Hedge fund | 1.3% | $77.0M | 5,100,000 | +7.8% shares | Q2 2026 |
| First Light Asset Management, LLCHedge fund | 3.1% | $51.1M | 3,383,553 | +157.4% shares | Q2 2026 |
| Paradice Investment Management LLCInstitutional asset manager | 5.5% | $32.7M | 2,007,415 | -0.8% shares | Q3 2026 |
| ArrowMark Colorado Holdings LLCHedge fund | 0.8% | $19.6M | 1,299,586 | -58.1% shares | Q2 2026 |
| DAFNA Capital Management LLCHedge fund | 1.0% | $5.4M | 355,208 | +0.0% shares | Q2 2026 |
| KVP Capital Advisors, LPHedge fund | 3.3% | $4.5M | 301,000 | New | Q2 2026 |
| Sector Gamma AsInvestment manager | 0.9% | $4.0M | 267,091 | +0.0% shares | Q2 2026 |
| Beaconlight Capital, LLCHedge fund | 1.8% | $4.0M | 266,009 | +4.8% shares | Q2 2026 |
| Nierenberg Investment Management Company, LLCHedge fund | 1.2% | $2.4M | 158,910 | +99.9% shares | Q2 2026 |
Each manager counts with its latest 13F (Q3 2026: 1, Q2 2026: 8). Screen TNDM in the grand portfolio →
TNDM stock trades by members of Congress
Members of Congress have disclosed 8 TNDM trades since 2015, 3 purchases and 0 sales in the past year; the latest was Gilbert Ray Cisneros, Jr. (D-CA), buying $1K–15K on Sep 29, 2026.
| Filed | Member | Trade | Amount | Traded | Since |
|---|---|---|---|---|---|
| Oct 12, 2026 | Gilbert Ray Cisneros, Jr.D-CA · House | Buy | $1K–15K | Sep 29, 2026 | +15.4% |
| Apr 7, 2026 | Gilbert Ray Cisneros, Jr.D-CA · House | Buy | $1K–15K | Mar 3, 2026 | -19.4% |
| Oct 15, 2025 | Josh GottheimerD-NJ · House | Buy | $1K–15K | Sep 22, 2025 | +46.5% |
| Apr 10, 2025 | Josh GottheimerD-NJ · House | Sale | $1K–15K | Mar 19, 2025 | -7.2% |
| Apr 7, 2025 | Gilbert Ray Cisneros, Jr.D-CA · House | Buy | $1K–15K | Mar 4, 2025 | -1.8% |
| Sep 11, 2024 | Josh GottheimerD-NJ · House | Buy | $1K–15K | Aug 5, 2024 | -53.1% |
| Aug 13, 2023 | Daniel S. GoldmanD-NY · House | Sale | $1K–15K | Jul 12, 2023 | -35.0% |
| Jun 7, 2015 | Thomas MacArthurR-NJ · House | Sale | $1K–15K | May 27, 2015 | -83.7% |
4 members have traded TNDM: Gilbert Ray Cisneros, Jr., Josh Gottheimer, Daniel S. Goldman, Thomas MacArthur.
Analysis mentioning TNDM
Posts from the blog that cover Tandem Diabetes Care Inc, newest first.
TNDM questions and answers
Are insiders buying TNDM stock?
Between Aug 1, 2026 and Oct 29, 2026, 1 TNDM insider filed 1 sale worth $33K on SEC Form 4, and no open-market purchases; 1 of the sales were pre-planned under Rule 10b5-1.
Which hedge funds own TNDM?
9 13F filers hold TNDM among their 50 largest positions, worth $200.7M combined. The biggest bets by portfolio weight are Paradice Investment Management LLC (5.5%), KVP Capital Advisors, LP (3.3%) and First Light Asset Management, LLC (3.1%). In their latest 13Fs, 1 manager opened a new position and 3 added to one.
Has Congress traded TNDM?
Members of Congress have disclosed 8 TNDM trades since 2015, 3 purchases and 0 sales in the past year; the latest was Gilbert Ray Cisneros, Jr. (D-CA), buying $1K–15K on Sep 29, 2026.
Who is the largest holder of TNDM?
Among 13F filers, Sessa Capital IM, L.P. reports the largest TNDM position, $77.0M (5,100,000 shares) in its Q2 2026 13F. The biggest bet by portfolio weight is Paradice Investment Management LLC's: 5.5% of its portfolio.
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