TANDEM DIABETES CARE INC TNDM
COM NEW · Common Stock · CUSIP 875372203 · ISIN US8753722037
U.S. healthcare company
- SectorHealth care
- IndustrySurgical & Medical Instruments & Apparatus
- HeadquartersSan Diego, CA
- Founded2008
- Websitetandemdiabetes.com
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($18.3m this quarter). Holder counts are more reliable. Shares outstanding: 65.7m as of 2024-11-01, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $36.02. Options: 14 managers hold calls ($113.7m notional), 11 hold puts ($7.4m).
Trends to Q4 2024
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 298 |
| Q4 2022 | 295 |
| Q1 2023 | 275 |
| Q2 2023 | 248 |
| Q3 2023 | 226 |
| Q4 2023 | 268 |
| Q1 2024 | 291 |
| Q2 2024 | 316 |
| Q3 2024 | 331 |
| Q4 2024 | 315 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2023 | 150 | 144 |
| Q2 2023 | 125 | 151 |
| Q3 2023 | 104 | 135 |
| Q4 2023 | 150 | 117 |
| Q1 2024 | 174 | 107 |
| Q2 2024 | 184 | 126 |
| Q3 2024 | 162 | 157 |
| Q4 2024 | 165 | 143 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2024 | $120.9m | $9.2m | 0.08 |
| Q2 2024 | $134.9m | $15.3m | 0.11 |
| Q3 2024 | $144.5m | $10.5m | 0.07 |
| Q4 2024 | $113.7m | $7.4m | 0.06 |
Biggest buyers
| Hood River Capital Management LLC | New | +1.3m |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Added | +1.1m |
| BROWN ADVISORY INC | New | +913.1k |
| BlackRock, Inc. | Added | +587.4k |
| Park West Asset Management LLC | Added | +530.0k |
| BAILLIE GIFFORD & CO | Added | +523.8k |
| FMR LLC | Added | +522.0k |
| UBS Group AG | Added | +400.9k |
| ArrowMark Colorado Holdings LLC | Added | +337.0k |
| GW&K Investment Management, LLC | Added | +323.7k |
Biggest sellers
| Capital World Investors | Reduced | -2.5m |
| MILLENNIUM MANAGEMENT LLC | Reduced | -1.3m |
| Bellevue Group AG | Reduced | -1.1m |
| JANUS HENDERSON GROUP PLC | Reduced | -883.7k |
| NEXT CENTURY GROWTH INVESTORS LLC | Reduced | -780.8k |
| Driehaus Capital Management LLC | Sold out | -777.6k |
| First Light Asset Management, LLC | Reduced | -733.2k |
| Divisadero Street Capital Management, LP | Reduced | -692.4k |
| AMERIPRISE FINANCIAL INC | Reduced | -525.2k |
| Jefferies Financial Group Inc. | Reduced | -369.2k |
Biggest calls
| UBS Group AG | Unchanged | $98.9m2.7m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $4.0m109.9k shares |
| JANE STREET GROUP, LLC | Reduced | $3.8m104.3k shares |
| CITADEL ADVISORS LLC | Reduced | $1.9m51.9k shares |
| Walleye Capital LLC | Reduced | $1.1m30.5k shares |
| WOLVERINE TRADING, LLC | Reduced | $966.0k26.2k shares |
| IMC-Chicago, LLC | Added | $756.4k21.0k shares |
| D. E. Shaw & Co., Inc. | New | $731.2k20.3k shares |
| SIMPLEX TRADING, LLC | Reduced | $597.0k16.6k shares |
| MILLENNIUM MANAGEMENT LLC | Unchanged | $360.2k10.0k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.0m83.4k shares |
| CITADEL ADVISORS LLC | Added | $1.9m52.0k shares |
| D. E. Shaw & Co., Inc. | New | $612.3k17.0k shares |
| IMC-Chicago, LLC | Added | $464.7k12.9k shares |
| Squarepoint Ops LLC | Added | $421.4k11.7k shares |
| WOLVERINE TRADING, LLC | Added | $291.3k7.9k shares |
| Cubist Systematic Strategies, LLC | Reduced | $244.9k6.8k shares |
| SIMPLEX TRADING, LLC | Added | $205.0k5.7k shares |
| GROUP ONE TRADING LLC | Added | $169.3k4.7k shares |
| Walleye Capital LLC | Reduced | $86.4k2.4k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BlackRock, Inc. 13G · institution filed 2025-04-29 | 15.2% |
| Sessa Capital (Master), L.P. 13G · passive investor new · filed 2025-05-15 | 6.7% |
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.9% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.2% |
Fell to 5% or below in the last year: Voya Financial, Inc. (0.2%, 2026-08-06), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC), ArrowMark Colorado Holdings LLC (4.3%, 2026-02-17)
Insider purchases and sales in Q4 2024
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q1 2023 | 0 | — | 1 | $411.9k | — |
| Q2 2023 | 3 | $484.0k | 0 | — | — |
| Q3 2023 | 1 | $21.4k | 0 | — | — |
| Q4 2023 | 3 | $220.1k | 0 | — | — |
| Q1 2024 | 0 | — | 0 | — | — |
| Q2 2024 | 0 | — | 1 | $258.4k | — |
| Q3 2024 | 0 | — | 0 | — | — |
| Q4 2024 | 1 | $12.4k | 1 | $1.2m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2024-11-21 | BLICKENSTAFF KIM D Director · See Footnote | Sold | $941.4k30.0k shares |
| 2024-11-20 | BLICKENSTAFF KIM D Director · See Footnote | Sold | $300.0k10.0k shares |
| 2024-11-15 | Novara Mark David EVP & CHIEF COMMERCIAL OFFICER | Bought | $12.4k532 shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q4 2024
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.01% of their portfolio | 11.7m $421.4m | Added +587.4k |
| VANGUARD GROUP INC 0.00% of their portfolio | 7.4m $268.0m | Added +77.5k |
| STATE STREET CORP 0.00% of their portfolio | 2.8m $99.6m | Added +109.4k |
| ArrowMark Colorado Holdings LLC 1.32% of their portfolio | 2.7m $98.1m | Added +337.0k |
| GW&K Investment Management, LLC 0.65% of their portfolio | 2.1m $76.5m | Added +323.7k |
| FRED ALGER MANAGEMENT, LLC 0.33% of their portfolio | 1.9m $70.0m | Reduced -35.8k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.21% of their portfolio | 1.7m $59.8m | Added +1.1m |
| Park West Asset Management LLC 4.80% of their portfolio | 1.6m $57.6m | Added +530.0k |
| Stephens Investment Management Group LLC 0.75% of their portfolio | 1.6m $56.0m | Added +281.3k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.5m $55.3m | Added +8.0k |
| JENNISON ASSOCIATES LLC 0.03% of their portfolio | 1.5m $52.8m | Reduced -315.6k |
| Champlain Investment Partners, LLC 0.31% of their portfolio | 1.4m $49.7m | Reduced -89.3k |
| Hood River Capital Management LLC 0.68% of their portfolio | 1.3m $46.0m | New |
| FMR LLC 0.00% of their portfolio | 1.1m $39.1m | Added +522.0k |
| Chicago Capital, LLC 0.93% of their portfolio | 970.6k $35.0m | Reduced -32.5k |
| Paradice Investment Management LLC 6.83% of their portfolio | 956.4k $34.4m | Added +53.0k |
| MARSHALL WACE, LLP 0.04% of their portfolio | 950.9k $34.3m | Added +137.4k |
| GILDER GAGNON HOWE & CO LLC 0.36% of their portfolio | 931.9k $33.6m | Added +58.9k |
| BROWN ADVISORY INC 0.04% of their portfolio | 913.1k $32.9m | New |
| TWO SIGMA ADVISERS, LP 0.07% of their portfolio | 881.8k $31.8m | Reduced -20.1k |
| TWO SIGMA INVESTMENTS, LP 0.07% of their portfolio | 861.2k $31.0m | Added +36.5k |
| MORGAN STANLEY 0.00% of their portfolio | 847.1k $30.5m | Reduced -145.6k |
| KINGDON CAPITAL MANAGEMENT, L.L.C. 4.87% of their portfolio | 790.5k $28.5m | Added +260.5k |
| Bellevue Group AG 0.54% of their portfolio | 782.5k $28.2m | Reduced -1.1m |
| Capital World Investors 0.00% of their portfolio | 767.0k $27.6m | Reduced -2.5m |
| BAILLIE GIFFORD & CO 0.02% of their portfolio | 746.1k $26.9m | Added +523.8k |
| Capital International Investors 0.00% of their portfolio | 718.0k $25.9m | Added +79.8k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 697.5k $25.1m | Added +61.8k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 678.5k $24.4m | Added +57.9k |
| BROWN CAPITAL MANAGEMENT LLC 0.54% of their portfolio | 642.0k $23.1m | Reduced -97.1k |
| UBS Group AG 0.01% of their portfolio | 626.4k $22.6m | Added +400.9k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 602.3k $21.7m | Added +16.3k |
| VICTORY CAPITAL MANAGEMENT INC 0.02% of their portfolio | 565.2k $20.4m | Reduced -22.0k |
| Nuveen Asset Management, LLC 0.01% of their portfolio | 519.0k $18.7m | Added +46.6k |
| Connor, Clark & Lunn Investment Management Ltd. 0.08% of their portfolio | 515.1k $18.6m | Added +243.0k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.86% of their portfolio | 506.6k $18.2m | Added +58.5k |
| Point72 Asset Management, L.P. 0.05% of their portfolio | 495.3k $17.8m | Added +254.6k |
| BARCLAYS PLC 0.01% of their portfolio | 477.0k $17.2m | Added +245.9k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 436.7k $15.7m | Added +4.1k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 392.6k $14.1m | Reduced -2.6k |
| PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio | 388.3k $14.0m | Added +18.0k |
| Divisadero Street Capital Management, LP 1.62% of their portfolio | 360.2k $13.0m | Reduced -692.4k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.08% of their portfolio | 346.6k $12.5m | Added +78.3k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 345.7k $12.5m | Reduced -525.2k |
| BEACONLIGHT CAPITAL, LLC 4.77% of their portfolio | 331.2k $11.9m | Added +115.6k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 317.7k $11.4m | Reduced -127.9k |
| RENAISSANCE TECHNOLOGIES LLC 0.02% of their portfolio | 315.7k $11.4m | Added +105.3k |
| Mirae Asset Global Investments Co., Ltd. 0.05% of their portfolio | 301.6k $11.1m | Added +241.0k |
| First Light Asset Management, LLC 1.01% of their portfolio | 292.1k $10.5m | Reduced -733.2k |
| Russell Investments Group, Ltd. 0.01% of their portfolio | 290.2k $10.5m | Added +77.6k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.09% of their portfolio | 272.1k $9.8m | Added +91.2k |
| KENNEDY CAPITAL MANAGEMENT LLC 0.21% of their portfolio | 267.4k $9.6m | Added +142.3k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 254.1k $9.2m | Reduced -11.6k |
| ExodusPoint Capital Management, LP 0.10% of their portfolio | 254.1k $9.2m | Added +195.2k |
| Aberdeen Group plc 0.02% of their portfolio | 248.9k $9.0m | Added +104.4k |
| DAFNA Capital Management LLC 2.04% of their portfolio | 223.2k $8.0m | Added +19.0k |
| Engineers Gate Manager LP 0.14% of their portfolio | 222.8k $8.0m | Added +143.7k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 212.2k $7.6m | Reduced -55.3k |
| Trexquant Investment LP 0.09% of their portfolio | 211.2k $7.6m | Added +73.8k |
| Invesco Ltd. 0.00% of their portfolio | 204.9k $7.4m | Reduced -112.7k |
| NEXT CENTURY GROWTH INVESTORS LLC 0.54% of their portfolio | 201.8k $7.3m | Reduced -780.8k |
| FIL Ltd 0.01% of their portfolio | 201.4k $7.3m | Added +66.0k |
| CAPITAL FUND MANAGEMENT S.A. 0.07% of their portfolio | 200.3k $7.2m | Added +107.6k |
| 4D Advisors, LLC 5.05% of their portfolio | 200.0k $7.2m | First filing |
| KBC Group NV 0.02% of their portfolio | 192.5k $6.9m | Added +56.5k |
| Legal & General Group Plc 0.00% of their portfolio | 182.7k $6.6m | Added +1.5k |
| Freestone Grove Partners LP 0.08% of their portfolio | 181.1k $6.5m | First filing |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 178.7k $6.4m | Reduced -4.8k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 177.7k $6.4m | Added +30.1k |
| PRUDENTIAL FINANCIAL INC 0.01% of their portfolio | 174.9k $5.7m | Added +39.8k |
| TUDOR INVESTMENT CORP ET AL 0.06% of their portfolio | 169.0k $6.1m | Added +128.3k |
| Public Sector Pension Investment Board 0.02% of their portfolio | 164.0k $5.9m | Added +25.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 163.6k $5.9m | First filing |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 162.3k $5.8m | Reduced -10.6k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 151.3k $5.5m | Reduced -1.3m |
| Polar Capital Holdings Plc 0.03% of their portfolio | 142.9k $5.1m | Reduced -11.1k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 142.5k $5.1m | Added +35.9k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 131.8k $4.7m | Reduced -216.0k |
| Swiss National Bank 0.00% of their portfolio | 128.7k $4.6m | Added +2.5k |
| FORMULA GROWTH LTD 1.54% of their portfolio | 126.0k $4.5m | Reduced -2.2k |
| SEI INVESTMENTS CO 0.01% of their portfolio | 123.8k $4.5m | Added +93.3k |
| TRUIST FINANCIAL CORP 0.01% of their portfolio | 119.6k $4.3m | Added +2.4k |
| Lisanti Capital Growth, LLC 1.03% of their portfolio | 118.5k $4.3m | Added +3.6k |
| Gotham Asset Management, LLC 0.04% of their portfolio | 115.9k $4.2m | Reduced -4.4k |
| RICE HALL JAMES & ASSOCIATES, LLC 0.21% of their portfolio | 105.5k $3.8m | Added +13.2k |
| Assenagon Asset Management S.A. 0.01% of their portfolio | 98.2k $3.5m | Reduced -279.3k |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 98.2k $3.5m | Added +68.6k |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.30% of their portfolio | 97.7k $3.5m | Added +29.6k |
| CITIGROUP INC 0.00% of their portfolio | 95.2k $3.4m | Added +13.2k |
| Cubist Systematic Strategies, LLC 0.06% of their portfolio | 94.0k $3.4m | Reduced -226.5k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 93.8k $3.4m | Reduced -40.6k |
| ALGERT GLOBAL LLC 0.08% of their portfolio | 89.5k $3.2m | Added +52.4k |
| BANQUE PICTET & CIE SA 0.03% of their portfolio | 87.3k $3.1m | Reduced -8.0k |
| MIZUHO MARKETS AMERICAS LLC 0.06% of their portfolio | 85.1k $3.1m | Added +14.0k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 77.9k $2.8m | Reduced -21.2k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.01% of their portfolio | 72.3k $2.6m | Reduced -7.6k |
| Amundi 0.00% of their portfolio | 69.9k $2.6m | Added +21.0k |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 68.2k $2.5m | Reduced -400 |
| NATIXIS ADVISORS, LLC 0.00% of their portfolio | 65.7k $2.4m | Added +2.0k |
| Squarepoint Ops LLC 0.01% of their portfolio | 63.3k $2.3m | Added +27.4k |