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 ($25.6m 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 ≈ $42.40. Options: 19 managers hold calls ($144.5m notional), 14 hold puts ($10.5m).
Trends to Q3 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 |
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 |
| Q2 2024 | 184 | 126 |
| Q3 2024 | 162 | 157 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q4 2023 | $13.2m | $18.3m | 1.38 |
| Q1 2024 | $120.9m | $9.2m | 0.08 |
| Q2 2024 | $134.9m | $15.3m | 0.11 |
| Q3 2024 | $144.5m | $10.5m | 0.07 |
Biggest buyers
| Divisadero Street Capital Management, LP | New | +1.1m |
| GW&K Investment Management, LLC | Added | +456.7k |
| GOLDMAN SACHS GROUP INC | Added | +428.8k |
| Park West Asset Management LLC | Added | +399.3k |
| MILLENNIUM MANAGEMENT LLC | Added | +380.7k |
| Cubist Systematic Strategies, LLC | New | +320.4k |
| First Light Asset Management, LLC | Added | +316.8k |
| Bellevue Group AG | Added | +307.6k |
| Jefferies Financial Group Inc. | Added | +293.6k |
| MARSHALL WACE, LLP | Added | +289.2k |
Biggest sellers
| CITADEL ADVISORS LLC | Reduced | -1.5m |
| JACOBS LEVY EQUITY MANAGEMENT, INC | Reduced | -669.5k |
| AMERIPRISE FINANCIAL INC | Reduced | -609.9k |
| JANUS HENDERSON GROUP PLC | Reduced | -536.6k |
| Capital World Investors | Reduced | -400.0k |
| FMR LLC | Reduced | -328.2k |
| TWO SIGMA INVESTMENTS, LP | Reduced | -310.5k |
| FIRST TRUST ADVISORS LP | Reduced | -279.8k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Sold out | -230.4k |
| TWO SIGMA ADVISERS, LP | Reduced | -229.7k |
Biggest calls
| UBS Group AG | Unchanged | $116.4m2.7m shares |
| Divisadero Street Capital Management, LP | New | $6.0m141.7k shares |
| JANE STREET GROUP, LLC | Reduced | $5.9m138.8k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $3.8m90.1k shares |
| CITADEL ADVISORS LLC | Reduced | $3.3m77.2k shares |
| Walleye Capital LLC | Reduced | $1.5m36.1k shares |
| PURA VIDA INVESTMENTS, LLC | New | $1.3m30.0k shares |
| WOLVERINE TRADING, LLC | Added | $1.2m27.3k shares |
| GOLDMAN SACHS GROUP INC | New | $1.2m27.2k shares |
| SIMPLEX TRADING, LLC | Reduced | $1.0m23.7k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $2.8m66.8k shares |
| JANE STREET GROUP, LLC | Added | $2.2m52.5k shares |
| MILLENNIUM MANAGEMENT LLC | Reduced | $1.3m30.0k shares |
| CITADEL ADVISORS LLC | Reduced | $873.6k20.6k shares |
| Cubist Systematic Strategies, LLC | Added | $763.4k18.0k shares |
| TWO SIGMA SECURITIES, LLC | Added | $508.9k12.0k shares |
| Squarepoint Ops LLC | Reduced | $470.8k11.1k shares |
| Walleye Capital LLC | Reduced | $470.8k11.1k shares |
| IMC-Chicago, LLC | New | $428.3k10.1k shares |
| WOLVERINE TRADING, LLC | Reduced | $263.2k6.2k 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 Q3 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 |
|---|---|---|---|---|---|
| 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 | — | — |
| Q2 2024 | 0 | — | 1 | $258.4k | — |
| Q3 2024 | 0 | — | 0 | — | — |
None reported in Q3 2024.
Holders, Q3 2024
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.01% of their portfolio | 11.1m $471.2m | First filing |
| VANGUARD GROUP INC 0.01% of their portfolio | 7.4m $312.2m | Reduced -15.4k |
| Capital World Investors 0.02% of their portfolio | 3.3m $138.5m | Reduced -400.0k |
| STATE STREET CORP 0.00% of their portfolio | 2.7m $112.6m | Added +83.2k |
| ArrowMark Colorado Holdings LLC 1.30% of their portfolio | 2.4m $101.2m | Reduced -118.2k |
| FRED ALGER MANAGEMENT, LLC 0.41% of their portfolio | 2.0m $83.9m | Reduced -195.0k |
| Bellevue Group AG 1.27% of their portfolio | 1.9m $78.5m | Added +307.6k |
| GW&K Investment Management, LLC 0.65% of their portfolio | 1.8m $76.3m | Added +456.7k |
| JENNISON ASSOCIATES LLC 0.05% of their portfolio | 1.8m $75.6m | Reduced -187.6k |
| GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio | 1.5m $64.7m | Added +18.2k |
| Champlain Investment Partners, LLC 0.38% of their portfolio | 1.5m $62.3m | Reduced -160.4k |
| MILLENNIUM MANAGEMENT LLC 0.05% of their portfolio | 1.4m $60.8m | Added +380.7k |
| Stephens Investment Management Group LLC 0.74% of their portfolio | 1.3m $54.1m | Added +138.3k |
| Park West Asset Management LLC 3.35% of their portfolio | 1.1m $45.4m | Added +399.3k |
| Divisadero Street Capital Management, LP 5.74% of their portfolio | 1.1m $44.6m | New |
| First Light Asset Management, LLC 3.62% of their portfolio | 1.0m $43.5m | Added +316.8k |
| Chicago Capital, LLC 1.18% of their portfolio | 1.0m $42.5m | Added +182.1k |
| MORGAN STANLEY 0.00% of their portfolio | 992.7k $42.1m | Reduced -26.7k |
| NEXT CENTURY GROWTH INVESTORS LLC 3.38% of their portfolio | 982.7k $41.7m | Added +68.3k |
| JANUS HENDERSON GROUP PLC 0.02% of their portfolio | 913.5k $38.7m | Reduced -536.6k |
| Paradice Investment Management LLC 6.67% of their portfolio | 903.4k $38.3m | Added +81.4k |
| TWO SIGMA ADVISERS, LP 0.09% of their portfolio | 901.9k $38.2m | Reduced -229.7k |
| GILDER GAGNON HOWE & CO LLC 0.44% of their portfolio | 873.0k $37.0m | Reduced -155.7k |
| AMERIPRISE FINANCIAL INC 0.01% of their portfolio | 870.8k $36.9m | Reduced -609.9k |
| TWO SIGMA INVESTMENTS, LP 0.08% of their portfolio | 824.7k $35.0m | Reduced -310.5k |
| MARSHALL WACE, LLP 0.04% of their portfolio | 813.6k $34.5m | Added +289.2k |
| Driehaus Capital Management LLC 0.28% of their portfolio | 777.6k $33.0m | Reduced -177.7k |
| BROWN CAPITAL MANAGEMENT LLC 0.67% of their portfolio | 739.1k $31.3m | Reduced -175.4k |
| Capital International Investors 0.01% of their portfolio | 638.2k $27.1m | Added +31.8k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 635.7k $27.0m | Added +271.1k |
| GOLDMAN SACHS GROUP INC 0.01% of their portfolio | 620.5k $26.3m | Added +428.8k |
| VICTORY CAPITAL MANAGEMENT INC 0.02% of their portfolio | 587.2k $24.9m | Added +183.9k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 586.1k $24.9m | Added +18.9k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.09% of their portfolio | 574.7k $24.4m | Reduced -669.5k |
| FMR LLC 0.00% of their portfolio | 564.9k $24.0m | Reduced -328.2k |
| KINGDON CAPITAL MANAGEMENT, L.L.C. 3.30% of their portfolio | 530.0k $22.5m | Added +161.0k |
| Nuveen Asset Management, LLC 0.01% of their portfolio | 472.4k $20.0m | Added +227.8k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.97% of their portfolio | 448.1k $19.0m | Added +166.1k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 445.6k $18.9m | Reduced -187.3k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 432.6k $18.3m | Reduced -61.8k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 395.2k $16.8m | Added +226.7k |
| Jefferies Financial Group Inc. 0.26% of their portfolio | 378.3k $16.0m | Added +293.6k |
| Assenagon Asset Management S.A. 0.03% of their portfolio | 377.6k $16.0m | Added +66.1k |
| PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio | 370.3k $15.7m | Reduced -77.8k |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 347.8k $14.8m | Reduced -1.5m |
| Cubist Systematic Strategies, LLC 0.21% of their portfolio | 320.4k $13.6m | New |
| Invesco Ltd. 0.00% of their portfolio | 317.6k $13.5m | Added +114.1k |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 293.6k $12.5m | Added +99.9k |
| Connor, Clark & Lunn Investment Management Ltd. 0.06% of their portfolio | 272.1k $11.5m | Added +66.7k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.08% of their portfolio | 268.2k $11.4m | Reduced -1.5k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.02% of their portfolio | 267.5k $11.3m | Reduced -117.0k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 265.7k $11.3m | Added +14.7k |
| Point72 Asset Management, L.P. 0.04% of their portfolio | 240.7k $10.2m | New |
| BARCLAYS PLC 0.00% of their portfolio | 231.1k $9.8m | Reduced -174.6k |
| UBS Group AG 0.00% of their portfolio | 225.5k $9.6m | Reduced -70.3k |
| BAILLIE GIFFORD & CO 0.01% of their portfolio | 222.3k $9.4m | Reduced -120 |
| BEACONLIGHT CAPITAL, LLC 3.76% of their portfolio | 215.6k $9.1m | Added +94.3k |
| Russell Investments Group, Ltd. 0.01% of their portfolio | 212.6k $9.0m | Reduced -20.2k |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 210.4k $8.9m | Reduced -85.4k |
| DAFNA Capital Management LLC 2.05% of their portfolio | 204.2k $8.7m | Unchanged |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 183.5k $7.8m | Reduced -3.2k |
| Legal & General Group Plc 0.00% of their portfolio | 181.2k $7.7m | Reduced -1.8k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.07% of their portfolio | 180.9k $7.7m | Reduced -1.4k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 172.9k $7.3m | Reduced -17.9k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.01% of their portfolio | 159.6k $6.8m | Added +94.6k |
| Polar Capital Holdings Plc 0.04% of their portfolio | 154.0k $6.5m | New |
| Integral Health Asset Management, LLC 0.75% of their portfolio | 150.0k $6.4m | New |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 147.6k $6.3m | Reduced -5.5k |
| Aberdeen Group plc 0.01% of their portfolio | 144.5k $6.1m | New |
| Public Sector Pension Investment Board 0.03% of their portfolio | 138.9k $5.9m | Reduced -3.2k |
| Trexquant Investment LP 0.07% of their portfolio | 137.4k $5.8m | Reduced -71.0k |
| KBC Group NV 0.02% of their portfolio | 136.0k $5.8m | Reduced -103.4k |
| FIL Ltd 0.01% of their portfolio | 135.4k $5.7m | Reduced -230 |
| PRUDENTIAL FINANCIAL INC 0.01% of their portfolio | 135.1k $5.7m | Added +13.8k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 134.4k $5.7m | Reduced -14.4k |
| FORMULA GROWTH LTD 1.87% of their portfolio | 128.1k $5.4m | Added +3.5k |
| Swiss National Bank 0.00% of their portfolio | 126.2k $5.4m | Reduced -800 |
| KENNEDY CAPITAL MANAGEMENT LLC 0.12% of their portfolio | 125.0k $5.3m | New |
| Gotham Asset Management, LLC 0.05% of their portfolio | 120.3k $5.1m | Reduced -10.4k |
| TRUIST FINANCIAL CORP 0.01% of their portfolio | 117.1k $5.0m | Added +7.9k |
| JANE STREET GROUP, LLC 0.01% of their portfolio | 115.4k $4.9m | Added +47.7k |
| Lisanti Capital Growth, LLC 1.23% of their portfolio | 114.9k $4.9m | Reduced -43.3k |
| Simplify Asset Management Inc. 0.33% of their portfolio | 114.6k $4.9m | New |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 106.6k $4.5m | Reduced -21.0k |
| RAYMOND JAMES & ASSOCIATES 0.00% of their portfolio | 104.4k $4.4m | Added +7.7k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 99.1k $4.2m | Reduced -279.8k |
| BANQUE PICTET & CIE SA 0.04% of their portfolio | 95.3k $4.0m | Reduced -66.9k |
| CAPITAL FUND MANAGEMENT S.A. 0.04% of their portfolio | 92.7k $3.9m | New |
| RICE HALL JAMES & ASSOCIATES, LLC 0.21% of their portfolio | 92.3k $3.9m | Reduced -1.0k |
| CITIGROUP INC 0.00% of their portfolio | 82.0k $3.5m | Reduced -27.6k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.01% of their portfolio | 79.9k $3.4m | Added +30.9k |
| Engineers Gate Manager LP 0.07% of their portfolio | 79.1k $3.4m | Reduced -17.0k |
| Lighthouse Investment Partners, LLC 0.17% of their portfolio | 76.2k $3.2m | New |
| MIZUHO MARKETS AMERICAS LLC 0.07% of their portfolio | 71.1k $3.0m | Reduced -1.2k |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 68.6k $2.9m | Reduced -300 |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.22% of their portfolio | 68.1k $2.9m | Added +30.2k |
| Aquatic Capital Management LLC 0.07% of their portfolio | 67.5k $2.9m | Added +17.7k |
| NATIXIS ADVISORS, LLC 0.01% of their portfolio | 63.7k $2.7m | Added +10.5k |
| Cerity Partners LLC 0.01% of their portfolio | 62.8k $2.7m | Added +11.2k |
| CANADA LIFE ASSURANCE Co 0.00% of their portfolio | 62.2k $2.6m | Reduced -16.6k |