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 ($7.9m this quarter). Holder counts are more reliable. Shares outstanding: 65.5m as of 2024-07-29, 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 ≈ $40.29. Options: 14 managers hold calls ($134.9m notional), 14 hold puts ($15.3m).
Trends to Q2 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 |
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 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2023 | $7.0m | $8.0m | 1.14 |
| Q4 2023 | $13.2m | $18.3m | 1.38 |
| Q1 2024 | $120.9m | $9.2m | 0.08 |
| Q2 2024 | $134.9m | $15.3m | 0.11 |
Biggest buyers
| BlackRock Inc. | Added | +1.9m |
| CITADEL ADVISORS LLC | Added | +1.2m |
| AMERIPRISE FINANCIAL INC | Added | +688.7k |
| FRED ALGER MANAGEMENT, LLC | Added | +677.0k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +431.5k |
| VICTORY CAPITAL MANAGEMENT INC | Added | +389.6k |
| BARCLAYS PLC | Added | +355.9k |
| STATE STREET CORP | Added | +331.6k |
| VANGUARD GROUP INC | Added | +325.4k |
| OBERWEIS ASSET MANAGEMENT INC/ | New | +282.0k |
Biggest sellers
| MORGAN STANLEY | Reduced | -3.2m |
| MARSHALL WACE, LLP | Reduced | -2.6m |
| JANUS HENDERSON GROUP PLC | Reduced | -750.6k |
| Park West Asset Management LLC | Reduced | -726.6k |
| JENNISON ASSOCIATES LLC | Reduced | -586.5k |
| Bellevue Group AG | Reduced | -488.6k |
| ArrowMark Colorado Holdings LLC | Reduced | -429.3k |
| Capital International Investors | Reduced | -410.7k |
| Driehaus Capital Management LLC | Reduced | -362.2k |
| Cubist Systematic Strategies, LLC | Sold out | -339.9k |
Biggest calls
| UBS Group AG | Unchanged | $110.6m2.7m shares |
| JANE STREET GROUP, LLC | Added | $6.3m157.5k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $5.3m131.1k shares |
| CITADEL ADVISORS LLC | Added | $4.1m101.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $2.2m55.6k shares |
| MILLENNIUM MANAGEMENT LLC | New | $1.6m40.0k shares |
| Walleye Capital LLC | Added | $1.6m38.7k shares |
| WOLVERINE TRADING, LLC | New | $846.1k21.0k shares |
| GTS SECURITIES LLC | Added | $725.2k18.0k shares |
| GROUP ONE TRADING LLC | Added | $656.7k16.3k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $5.2m129.4k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $2.8m70.0k shares |
| CITADEL ADVISORS LLC | Added | $2.4m60.0k shares |
| Walleye Capital LLC | Added | $1.1m27.8k shares |
| SIMPLEX TRADING, LLC | Added | $745.0k18.5k shares |
| GROUP ONE TRADING LLC | Added | $495.6k12.3k shares |
| WOLVERINE TRADING, LLC | New | $479.5k11.9k shares |
| Squarepoint Ops LLC | Added | $455.3k11.3k shares |
| BOOTHBAY FUND MANAGEMENT, LLC | Reduced | $419.0k10.4k shares |
| TWO SIGMA SECURITIES, LLC | Added | $411.0k10.2k 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 Q2 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 |
|---|---|---|---|---|---|
| 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 | — | — |
| Q2 2024 | 0 | — | 1 | $258.4k | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2024-05-30 | Allen Dick Director · See Footnote | Sold | $258.4k5.0k 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, Q2 2024
| Manager | Shares | Change |
|---|---|---|
| BlackRock Inc. 0.01% of their portfolio | 11.1m $448.1m | Added +1.9m |
| VANGUARD GROUP INC 0.01% of their portfolio | 7.4m $297.3m | Added +325.4k |
| Capital World Investors 0.02% of their portfolio | 3.7m $147.7m | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 2.6m $103.6m | Added +331.6k |
| ArrowMark Colorado Holdings LLC 1.20% of their portfolio | 2.5m $100.9m | Reduced -429.3k |
| FRED ALGER MANAGEMENT, LLC 0.43% of their portfolio | 2.2m $87.6m | Added +677.0k |
| JENNISON ASSOCIATES LLC 0.05% of their portfolio | 2.0m $79.4m | Reduced -586.5k |
| CITADEL ADVISORS LLC 0.07% of their portfolio | 1.8m $72.9m | Added +1.2m |
| Champlain Investment Partners, LLC 0.40% of their portfolio | 1.6m $65.7m | Added +116.0k |
| Bellevue Group AG 1.01% of their portfolio | 1.5m $62.2m | Reduced -488.6k |
| GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio | 1.5m $60.8m | Added +431.5k |
| AMERIPRISE FINANCIAL INC 0.02% of their portfolio | 1.5m $59.6m | Added +688.7k |
| JANUS HENDERSON GROUP PLC 0.03% of their portfolio | 1.5m $58.4m | Reduced -750.6k |
| GW&K Investment Management, LLC 0.49% of their portfolio | 1.3m $54.1m | Added +37.2k |
| JACOBS LEVY EQUITY MANAGEMENT, INC 0.21% of their portfolio | 1.2m $50.1m | Added +24.9k |
| Stephens Investment Management Group LLC 0.64% of their portfolio | 1.1m $45.8m | Added +173.7k |
| TWO SIGMA INVESTMENTS, LP 0.11% of their portfolio | 1.1m $45.7m | Added +113.2k |
| TWO SIGMA ADVISERS, LP 0.10% of their portfolio | 1.1m $45.6m | Added +54.7k |
| MILLENNIUM MANAGEMENT LLC 0.04% of their portfolio | 1.1m $42.5m | Added +29.0k |
| GILDER GAGNON HOWE & CO LLC 0.52% of their portfolio | 1.0m $41.4m | Added +131.2k |
| MORGAN STANLEY 0.00% of their portfolio | 1.0m $41.1m | Reduced -3.2m |
| Driehaus Capital Management LLC 0.37% of their portfolio | 955.2k $38.5m | Reduced -362.2k |
| BROWN CAPITAL MANAGEMENT LLC 0.74% of their portfolio | 914.5k $36.8m | Reduced -40.1k |
| NEXT CENTURY GROWTH INVESTORS LLC 3.06% of their portfolio | 914.4k $36.8m | Added +61.5k |
| FMR LLC 0.00% of their portfolio | 893.1k $36.0m | Reduced -157.3k |
| Paradice Investment Management LLC 5.86% of their portfolio | 822.0k $33.1m | Unchanged |
| Chicago Capital, LLC 0.98% of their portfolio | 821.1k $33.1m | Added +149.8k |
| First Light Asset Management, LLC 2.50% of their portfolio | 708.5k $28.5m | Added +233.4k |
| Park West Asset Management LLC 2.11% of their portfolio | 670.7k $27.0m | Reduced -726.6k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 632.9k $25.5m | Added +96.7k |
| Capital International Investors 0.01% of their portfolio | 606.5k $24.4m | Reduced -410.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 567.2k $22.9m | Added +149.6k |
| MARSHALL WACE, LLP 0.03% of their portfolio | 524.4k $21.1m | Reduced -2.6m |
| Bank of New York Mellon Corp 0.00% of their portfolio | 494.3k $19.9m | Added +73.4k |
| PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio | 448.1k $18.1m | Added +91.7k |
| BARCLAYS PLC 0.01% of their portfolio | 405.7k $16.3m | Added +355.9k |
| VICTORY CAPITAL MANAGEMENT INC 0.02% of their portfolio | 403.4k $16.3m | Added +389.6k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.02% of their portfolio | 384.5k $15.5m | Added +74.6k |
| FIRST TRUST ADVISORS LP 0.02% of their portfolio | 378.9k $15.3m | Added +36.0k |
| KINGDON CAPITAL MANAGEMENT, L.L.C. 2.30% of their portfolio | 369.0k $14.9m | Reduced -124.1k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 364.5k $14.7m | Added +22.0k |
| Assenagon Asset Management S.A. 0.03% of their portfolio | 311.4k $12.5m | Added +85.0k |
| RENAISSANCE TECHNOLOGIES LLC 0.02% of their portfolio | 295.8k $11.9m | Reduced -298.5k |
| UBS Group AG 0.00% of their portfolio | 295.8k $11.9m | Added +255.1k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.70% of their portfolio | 282.0k $11.4m | New |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.07% of their portfolio | 269.8k $10.9m | Added +3.6k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 251.0k $10.1m | Added +19.0k |
| Nuveen Asset Management, LLC 0.00% of their portfolio | 244.6k $9.9m | Added +100.7k |
| KBC Group NV 0.03% of their portfolio | 239.4k $9.6m | Reduced -530 |
| Russell Investments Group, Ltd. 0.02% of their portfolio | 232.9k $9.4m | Reduced -10.8k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.03% of their portfolio | 230.4k $9.3m | Reduced -291.2k |
| BAILLIE GIFFORD & CO 0.01% of their portfolio | 222.4k $9.0m | Reduced -37.3k |
| Trexquant Investment LP 0.13% of their portfolio | 208.4k $8.4m | Reduced -24.7k |
| Connor, Clark & Lunn Investment Management Ltd. 0.03% of their portfolio | 205.4k $8.3m | Added +34.0k |
| DAFNA Capital Management LLC 1.97% of their portfolio | 204.2k $8.2m | Reduced -54.0k |
| Invesco Ltd. 0.00% of their portfolio | 203.5k $8.2m | Reduced -49.4k |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 193.7k $7.8m | Added +47.9k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 191.7k $7.7m | Added +72.9k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 190.7k $7.7m | Added +107.4k |
| RHUMBLINE ADVISERS 0.01% of their portfolio | 186.8k $7.5m | Added +25.4k |
| Legal & General Group Plc 0.00% of their portfolio | 182.9k $7.4m | Added +2.4k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.07% of their portfolio | 182.2k $7.3m | Reduced -2.1k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 168.5k $6.8m | Reduced -18.9k |
| BANQUE PICTET & CIE SA 0.07% of their portfolio | 162.3k $6.5m | Reduced -46.6k |
| Lisanti Capital Growth, LLC 1.53% of their portfolio | 158.3k $6.4m | Reduced -16.6k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 153.2k $6.2m | Added +49.4k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 148.9k $6.0m | Added +60.9k |
| Public Sector Pension Investment Board 0.04% of their portfolio | 142.1k $5.7m | Added +8.4k |
| FIL Ltd 0.01% of their portfolio | 135.6k $5.5m | New |
| Gotham Asset Management, LLC 0.07% of their portfolio | 130.7k $5.3m | Added +7.5k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.01% of their portfolio | 127.6k $5.1m | Added +24.4k |
| Swiss National Bank 0.00% of their portfolio | 127.0k $5.1m | Reduced -1.2k |
| FORMULA GROWTH LTD 1.82% of their portfolio | 124.6k $5.0m | Added +900 |
| PRUDENTIAL FINANCIAL INC 0.01% of their portfolio | 121.3k $4.9m | Reduced -21.2k |
| BEACONLIGHT CAPITAL, LLC 2.48% of their portfolio | 121.3k $4.9m | Reduced -125.9k |
| Man Group plc 0.01% of their portfolio | 121.2k $4.9m | Added +100.1k |
| Squarepoint Ops LLC 0.02% of their portfolio | 121.2k $4.9m | Reduced -292.8k |
| ExodusPoint Capital Management, LP 0.05% of their portfolio | 118.6k $4.8m | New |
| Skandinaviska Enskilda Banken AB (publ) 0.02% of their portfolio | 118.2k $4.8m | Unchanged |
| CITIGROUP INC 0.00% of their portfolio | 109.7k $4.4m | Added +32.8k |
| TRUIST FINANCIAL CORP 0.01% of their portfolio | 109.2k $4.4m | Reduced -4.3k |
| Nicholas Investment Partners, LP 0.41% of their portfolio | 98.1k $4.0m | New |
| RAYMOND JAMES & ASSOCIATES 0.00% of their portfolio | 96.7k $3.9m | Reduced -177 |
| Engineers Gate Manager LP 0.09% of their portfolio | 96.1k $3.9m | Added +11.1k |
| RICE HALL JAMES & ASSOCIATES, LLC 0.23% of their portfolio | 93.3k $3.8m | Reduced -847 |
| Jefferies Financial Group Inc. 0.07% of their portfolio | 84.8k $3.4m | Added +54.8k |
| MACQUARIE GROUP LTD 0.00% of their portfolio | 83.8k $3.4m | New |
| Informed Momentum Co LLC 0.52% of their portfolio | 79.6k $3.2m | New |
| CANADA LIFE ASSURANCE Co 0.01% of their portfolio | 78.8k $3.2m | Reduced -855 |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC 0.07% of their portfolio | 77.8k $3.1m | Added +40.1k |
| SG Americas Securities, LLC 0.02% of their portfolio | 77.6k $3.1m | Reduced -70.0k |
| MIZUHO MARKETS AMERICAS LLC 0.08% of their portfolio | 72.3k $2.9m | New |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.01% of their portfolio | 68.9k $2.8m | Reduced -1.1k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 67.7k $2.7m | Reduced -240.4k |
| TUDOR INVESTMENT CORP ET AL 0.03% of their portfolio | 65.2k $2.6m | Reduced -12.1k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.00% of their portfolio | 65.0k $2.6m | Reduced -53.7k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 63.0k $2.5m | Reduced -2.2k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 56.2k $2.3m | Added +14.7k |
| Walleye Capital LLC 0.02% of their portfolio | 55.8k $2.2m | Added +50.8k |
| Thrivent Financial for Lutherans 0.00% of their portfolio | 53.6k $2.2m | Reduced -3.0k |