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 ($9.2m this quarter). Holder counts are more reliable. Shares outstanding: 64.6m as of 2024-04-26, 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 ≈ $35.42. Options: 13 managers hold calls ($120.9m notional), 12 hold puts ($9.2m).
Trends to Q1 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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2022 | 150 | 149 |
| Q1 2023 | 150 | 144 |
| Q2 2023 | 125 | 151 |
| Q3 2023 | 104 | 135 |
| Q4 2023 | 150 | 117 |
| Q1 2024 | 174 | 107 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2023 | $4.6m | $7.0m | 1.52 |
| Q3 2023 | $7.0m | $8.0m | 1.14 |
| Q4 2023 | $13.2m | $18.3m | 1.38 |
| Q1 2024 | $120.9m | $9.2m | 0.08 |
Biggest buyers
| MARSHALL WACE, LLP | Added | +2.8m |
| MORGAN STANLEY | Added | +2.5m |
| Park West Asset Management LLC | New | +1.4m |
| Driehaus Capital Management LLC | New | +1.3m |
| JENNISON ASSOCIATES LLC | Added | +1.3m |
| FRED ALGER MANAGEMENT, LLC | Added | +1.2m |
| GILDER GAGNON HOWE & CO LLC | Added | +879.3k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +576.1k |
| AMERIPRISE FINANCIAL INC | Added | +478.5k |
| BANK OF AMERICA CORP /DE/ | Added | +453.3k |
Biggest sellers
| EMINENCE CAPITAL, LP | Sold out | -5.2m |
| Capital World Investors | Reduced | -2.7m |
| FMR LLC | Reduced | -1.9m |
| Point72 Asset Management, L.P. | Reduced | -955.3k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Reduced | -430.9k |
| JANUS HENDERSON GROUP PLC | Reduced | -376.9k |
| Coronation Fund Managers Ltd. | Sold out | -376.4k |
| Alberta Investment Management Corp | Sold out | -262.6k |
| Paradice Investment Management LLC | Reduced | -259.9k |
| Invenomic Capital Management LP | Sold out | -241.0k |
Biggest calls
| UBS Group AG | New | $97.2m2.7m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $11.0m310.9k shares |
| CITADEL ADVISORS LLC | Added | $3.1m88.4k shares |
| SIMPLEX TRADING, LLC | Added | $2.9m82.6k shares |
| JANE STREET GROUP, LLC | Added | $2.5m71.1k shares |
| Cubist Systematic Strategies, LLC | Added | $1.9m53.7k shares |
| BARCLAYS PLC | New | $736.5k20.8k shares |
| TWO SIGMA SECURITIES, LLC | Reduced | $531.1k15.0k shares |
| GROUP ONE TRADING LLC | Added | $396.6k11.2k shares |
| GTS SECURITIES LLC | New | $354.1k10.0k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $4.4m124.3k shares |
| Cubist Systematic Strategies, LLC | Added | $1.7m47.6k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $1.1m30.0k shares |
| CITADEL ADVISORS LLC | Reduced | $538.2k15.2k shares |
| Squarepoint Ops LLC | New | $393.1k11.1k shares |
| BOOTHBAY FUND MANAGEMENT, LLC | Reduced | $389.5k11.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $269.0k7.6k shares |
| TWO SIGMA SECURITIES, LLC | Reduced | $230.2k6.5k shares |
| Walleye Trading LLC | Reduced | $77.9k2.2k shares |
| GROUP ONE TRADING LLC | Reduced | $67.3k1.9k 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 Q1 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 |
|---|---|---|---|---|---|
| Q2 2022 | 3 | $511.0k | 4 | $1.9m | — |
| Q3 2022 | 0 | — | 0 | — | — |
| Q4 2022 | 0 | — | 1 | $1.0m | — |
| 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 | — | — |
None reported in Q1 2024.
Holders, Q1 2024
| Manager | Shares | Change |
|---|---|---|
| BlackRock Inc. 0.01% of their portfolio | 9.2m $326.9m | Reduced -13.2k |
| VANGUARD GROUP INC 0.00% of their portfolio | 7.1m $249.7m | Added +30.7k |
| MORGAN STANLEY 0.00% of their portfolio | 4.2m $148.5m | Added +2.5m |
| Capital World Investors 0.02% of their portfolio | 3.7m $129.8m | Reduced -2.7m |
| MARSHALL WACE, LLP 0.18% of their portfolio | 3.1m $110.5m | Added +2.8m |
| ArrowMark Colorado Holdings LLC 1.17% of their portfolio | 2.9m $103.9m | Reduced -824 |
| JENNISON ASSOCIATES LLC 0.06% of their portfolio | 2.6m $90.5m | Added +1.3m |
| STATE STREET CORP 0.00% of their portfolio | 2.2m $79.4m | Reduced -33.6k |
| JANUS HENDERSON GROUP PLC 0.04% of their portfolio | 2.2m $77.9m | Reduced -376.9k |
| Bellevue Group AG 1.10% of their portfolio | 2.0m $71.9m | Added +39.6k |
| Champlain Investment Partners, LLC 0.31% of their portfolio | 1.5m $53.6m | Reduced -16.3k |
| FRED ALGER MANAGEMENT, LLC 0.26% of their portfolio | 1.5m $53.0m | Added +1.2m |
| Park West Asset Management LLC 3.71% of their portfolio | 1.4m $49.5m | New |
| Driehaus Capital Management LLC 0.46% of their portfolio | 1.3m $46.7m | New |
| GW&K Investment Management, LLC 0.41% of their portfolio | 1.3m $46.2m | Added +79.2k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.19% of their portfolio | 1.2m $43.2m | Reduced -71.8k |
| TWO SIGMA ADVISERS, LP 0.09% of their portfolio | 1.1m $38.1m | Added +75.3k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 1.1m $38.1m | Added +36.4k |
| FMR LLC 0.00% of their portfolio | 1.1m $37.2m | Reduced -1.9m |
| MILLENNIUM MANAGEMENT LLC 0.03% of their portfolio | 1.0m $36.3m | Added +394.1k |
| TWO SIGMA INVESTMENTS, LP 0.09% of their portfolio | 1.0m $36.2m | Added +320.6k |
| Capital International Investors 0.01% of their portfolio | 1.0m $36.0m | Reduced -66.4k |
| Stephens Investment Management Group LLC 0.45% of their portfolio | 962.6k $34.1m | Added +287 |
| BROWN CAPITAL MANAGEMENT LLC 0.60% of their portfolio | 954.6k $33.8m | Added +219.9k |
| GILDER GAGNON HOWE & CO LLC 0.40% of their portfolio | 897.4k $31.8m | Added +879.3k |
| NEXT CENTURY GROWTH INVESTORS LLC 2.62% of their portfolio | 852.9k $30.2m | Added +391.4k |
| Paradice Investment Management LLC 5.05% of their portfolio | 822.0k $29.1m | Reduced -259.9k |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 792.0k $28.1m | Added +478.5k |
| Chicago Capital, LLC 0.72% of their portfolio | 671.3k $23.8m | Added +194.4k |
| RENAISSANCE TECHNOLOGIES LLC 0.03% of their portfolio | 594.3k $21.0m | Added +576.1k |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 567.1k $20.1m | Added +206.4k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 536.2k $19.0m | Added +453.3k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.07% of their portfolio | 521.6k $18.5m | Reduced -430.9k |
| KINGDON CAPITAL MANAGEMENT, L.L.C. 2.31% of their portfolio | 493.1k $17.5m | Added +104.7k |
| First Light Asset Management, LLC 1.29% of their portfolio | 475.1k $16.8m | Added +114.8k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 420.9k $14.9m | Reduced -24.6k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 417.5k $14.8m | Added +20.8k |
| Squarepoint Ops LLC 0.06% of their portfolio | 414.0k $14.7m | Reduced -42.6k |
| PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio | 356.4k $12.6m | Added +12.0k |
| FIRST TRUST ADVISORS LP 0.01% of their portfolio | 342.9k $12.1m | New |
| NORTHERN TRUST CORP 0.00% of their portfolio | 342.5k $12.1m | Reduced -8.3k |
| Cubist Systematic Strategies, LLC 0.14% of their portfolio | 339.9k $12.0m | New |
| Tri Locum Partners LP 4.01% of their portfolio | 326.5k $11.6m | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio | 309.9k $11.0m | Reduced -5.6k |
| JANE STREET GROUP, LLC 0.01% of their portfolio | 308.1k $10.9m | Added +117.4k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.06% of their portfolio | 266.2k $9.4m | Added +10.9k |
| BAILLIE GIFFORD & CO 0.01% of their portfolio | 259.7k $9.2m | Reduced -2.9k |
| DAFNA Capital Management LLC 2.08% of their portfolio | 258.2k $9.1m | Added +37.5k |
| Invesco Ltd. 0.00% of their portfolio | 252.9k $9.0m | Added +7.2k |
| BEACONLIGHT CAPITAL, LLC 3.93% of their portfolio | 247.2k $8.8m | Added +180.9k |
| Russell Investments Group, Ltd. 0.01% of their portfolio | 243.7k $8.6m | Reduced -3.7k |
| KBC Group NV 0.03% of their portfolio | 239.9k $8.5m | Unchanged |
| Balyasny Asset Management L.P. 0.02% of their portfolio | 234.5k $8.3m | Added +128.1k |
| Trexquant Investment LP 0.16% of their portfolio | 233.1k $8.3m | Added +71.1k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 232.0k $8.2m | Added +46.9k |
| Assenagon Asset Management S.A. 0.02% of their portfolio | 226.4k $8.0m | New |
| Integral Health Asset Management, LLC 0.78% of their portfolio | 225.0k $8.0m | New |
| BANQUE PICTET & CIE SA 0.08% of their portfolio | 208.9k $7.4m | Added +10.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 187.3k $6.6m | Added +14.5k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.06% of their portfolio | 184.3k $6.5m | Added +38.4k |
| Legal & General Group Plc 0.00% of their portfolio | 180.6k $6.4m | Reduced -786 |
| Lisanti Capital Growth, LLC 1.51% of their portfolio | 174.8k $6.2m | Added +68.9k |
| Connor, Clark & Lunn Investment Management Ltd. 0.03% of their portfolio | 171.4k $6.1m | Reduced -13.0k |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 161.4k $5.7m | Reduced -10.7k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.01% of their portfolio | 152.2k $5.4m | Added +38.5k |
| SG Americas Securities, LLC 0.03% of their portfolio | 147.6k $5.2m | New |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 145.8k $5.2m | Added +136.6k |
| Nuveen Asset Management, LLC 0.00% of their portfolio | 143.9k $5.1m | Reduced -1.2k |
| PRUDENTIAL FINANCIAL INC 0.01% of their portfolio | 142.6k $5.0m | Added +33.6k |
| Mirae Asset Global Investments Co., Ltd. 0.01% of their portfolio | 139.5k $5.4m | Added +8.6k |
| Public Sector Pension Investment Board 0.03% of their portfolio | 133.7k $4.7m | Reduced -1.4k |
| Swiss National Bank 0.00% of their portfolio | 128.2k $4.5m | Unchanged |
| FORMULA GROWTH LTD 1.40% of their portfolio | 123.7k $4.4m | Added +83.0k |
| Gotham Asset Management, LLC 0.07% of their portfolio | 123.3k $4.4m | Added +48.0k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 118.8k $4.2m | Reduced -106.9k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.01% of their portfolio | 118.7k $4.2m | New |
| Skandinaviska Enskilda Banken AB (publ) 0.02% of their portfolio | 118.2k $4.2m | Unchanged |
| TRUIST FINANCIAL CORP 0.01% of their portfolio | 113.5k $4.0m | Added +26.0k |
| Holocene Advisors, LP 0.01% of their portfolio | 104.1k $3.7m | New |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 103.8k $3.7m | Added +11.3k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 103.3k $3.7m | Reduced -12.8k |
| RAYMOND JAMES & ASSOCIATES 0.00% of their portfolio | 96.8k $3.4m | Added +4.9k |
| HRT FINANCIAL LP 0.02% of their portfolio | 96.3k $3.4m | Added +29.0k |
| RICE HALL JAMES & ASSOCIATES, LLC 0.19% of their portfolio | 94.1k $3.3m | Reduced -10.3k |
| CREDIT SUISSE AG/ 0.00% of their portfolio | 90.8k $3.2m | Added +1.6k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 87.9k $3.1m | Reduced -55.8k |
| Engineers Gate Manager LP 0.08% of their portfolio | 84.9k $3.0m | New |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 83.3k $3.0m | Added +14.9k |
| Jump Financial, LLC 0.08% of their portfolio | 80.1k $2.8m | Added +41.0k |
| CANADA LIFE ASSURANCE Co 0.01% of their portfolio | 79.6k $2.8m | Reduced -1.2k |
| TUDOR INVESTMENT CORP ET AL 0.03% of their portfolio | 77.3k $2.7m | Reduced -154.4k |
| CITIGROUP INC 0.00% of their portfolio | 76.8k $2.7m | Added +33.9k |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.18% of their portfolio | 76.0k $2.7m | Added +68.1k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 71.4k $2.5m | Reduced -21.7k |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 70.0k $2.5m | Unchanged |
| Amundi 0.00% of their portfolio | 68.3k $2.1m | New |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.01% of their portfolio | 68.2k $2.8m | Added +2.7k |
| Schonfeld Strategic Advisors LLC 0.02% of their portfolio | 66.7k $2.4m | Added +12.0k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 65.2k $2.3m | Reduced -3.5k |
| CAPITAL FUND MANAGEMENT S.A. 0.03% of their portfolio | 61.9k $2.2m | New |