Latest Period
Q1 2026
Security Snapshot
TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM) Institutional Ownership
CUSIP: 875372203
13F Institutional Holders and Ownership History from Q1 2016 to Q1 2026
Institutions Reporting
273
Shares (Excl. Options)
78,656,848
Price
$19.17
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- Security type / class
- Equity / Common Stock, par value $0.001 per share
- Symbol
- TNDM on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 78,656,848
- Total 13F value
- $1,508,280,672
- Portfolio coverage rank
- 0%
- Share change
- +4,610,742
- Value change
- +$81,604,146
- Number of holders
- 273
- Shares outstanding
- 68,947,349
- SEC-reported price per share
- $19.42
- Insider filing price
- $19.42
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- TNDM - TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share is tracked under CUSIP 875372203.
- 273 institutions reported positions in Q1 2026.
- 6 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 268 to 273 between Q4 2025 and Q1 2026.
- SEC-reported value moved from $1,645,564,444 to $1,508,280,672.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 273 institutions filings for Q1 2026.
Security key
875372203
Latest holder period
Q1 2026
13F holders
273
13D/G owners
6
CIK / CUSIP context first
Open Q1 2026 holders
TNDM full holder history
TANDEM DIABETES CARE INC SEC filings
TANDEM DIABETES CARE INC company facts
TANDEM DIABETES CARE INC insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 875372203:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
6
Security
TNDM
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| BlackRock, Inc. | 15% | $176,563,735 | 10,106,682 | BlackRock, Inc. | 31 Mar 2025 | |||
| Sessa Capital (Master), L.P. | 6.7% | $78,026,383 | 4,466,307 | Sessa Capital (Master), L.P. | 31 Mar 2025 | |||
| Voya Financial, Inc. | 6.3% | $79,402,525 | 4,343,683 | Voya Financial, Inc. | 31 Mar 2026 | |||
| VANGUARD PORTFOLIO MANAGEMENT LLC | 5.9% | $77,682,093 | 4,052,274 | Vanguard Portfolio Management | 31 Mar 2026 | |||
| VANGUARD CAPITAL MANAGEMENT LLC | 5.2% | $68,125,809 | 3,553,772 | Vanguard Capital Management | 31 Mar 2026 | |||
| ArrowMark Colorado Holdings LLC | 4.3% | -24% | $62,272,841 | -$17,272,476 | 2,889,691 | -22% | ArrowMark Colorado Holdings, LLC | 31 Dec 2025 |
As of 31 Mar 2026, 273 institutional investors reported holding 78,656,848 shares of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM). This represents 114% of the company’s total 68,947,349 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
85%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| BlackRock, Inc. | 16% | 10,690,844 | -4.1% | 0% | $204,943,480 |
| Sessa Capital IM, L.P. | 6.9% | 4,730,757 | -5.4% | 1.7% | $90,688,612 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 5.8% | 3,993,333 | 0% | 0% | $76,552,194 |
| ArrowMark Colorado Holdings LLC | 4.5% | 3,103,609 | +7.4% | 1.6% | $59,496,185 |
| VANGUARD CAPITAL MANAGEMENT LLC | 4.4% | 3,038,919 | 0% | 0% | $58,256,077 |
| GW&K Investment Management, LLC | 3.9% | 2,689,106 | +0.52% | 0.45% | $51,550,000 |
| STATE STREET CORP | 3.9% | 2,662,260 | +0.78% | 0% | $51,035,524 |
| Driehaus Capital Management LLC | 3.3% | 2,304,414 | +43% | 0.32% | $44,175,616 |
| GOLDMAN SACHS GROUP INC | 3.2% | 2,218,922 | +32% | 0.01% | $42,536,734 |
| CITADEL ADVISORS LLC | 3.2% | 2,192,667 | +5% | 0.03% | $42,033,426 |
| UBS Group AG | 3% | 2,047,801 | +390% | 0.01% | $39,256,344 |
| Paradice Investment Management LLC | 3% | 2,042,425 | -1.7% | 7.4% | $39,153,287 |
| TWO SIGMA INVESTMENTS, LP | 2.7% | 1,864,194 | +55% | 0.03% | $35,736,599 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.4% | 1,679,863 | +1.8% | 0% | $32,209,339 |
| JENNISON ASSOCIATES LLC | 2.4% | 1,658,448 | -18% | 0.02% | $31,792,448 |
| JACOBS LEVY EQUITY MANAGEMENT, INC | 2.2% | 1,523,946 | -7.8% | 0.12% | $29,214,045 |
| MARSHALL WACE, LLP | 2.1% | 1,442,472 | +65% | 0.03% | $27,652,189 |
| MORGAN STANLEY | 2% | 1,357,542 | -35% | 0% | $26,024,095 |
| Freestone Grove Partners LP | 1.9% | 1,330,742 | -7.8% | 0.18% | $25,510,324 |
| First Light Asset Management, LLC | 1.9% | 1,314,715 | +21% | 2.3% | $25,203,087 |
| BAILLIE GIFFORD & CO | 1.6% | 1,089,393 | -4.9% | 0.02% | $20,883,664 |
| WELLINGTON MANAGEMENT GROUP LLP | 1.5% | 1,042,764 | +961% | 0% | $19,989,786 |
| VOYA INVESTMENT MANAGEMENT LLC | 1.2% | 804,137 | +152% | 0.02% | $15,415,306 |
| D. E. Shaw & Co., Inc. | 1.1% | 783,906 | -8.2% | 0.01% | $15,027,478 |
| Soleus Capital Management, L.P. | 1.1% | 783,000 | 0.61% | $15,010,110 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
37
Latest
Q1 2026
Rows shown
1-25 of 37
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 78,656,848 | $1,508,280,672 | +$81,604,146 | $19.17 | 273 |
| 2025 Q4 | 74,868,421 | $1,645,564,444 | +$37,201,810 | $21.98 | 268 |
| 2025 Q3 | 75,062,169 | $911,087,579 | -$138,652,756 | $12.14 | 251 |
| 2025 Q2 | 80,970,548 | $1,506,919,626 | +$146,515,993 | $18.64 | 269 |
| 2025 Q1 | 73,028,420 | $1,399,471,204 | -$74,262,859 | $19.16 | 271 |
| 2024 Q4 | 72,082,680 | $2,596,593,509 | -$54,203,387 | $36.02 | 311 |
| 2024 Q3 | 73,070,303 | $3,098,544,283 | -$23,063,732 | $42.41 | 326 |
| 2024 Q2 | 73,624,715 | $2,966,330,226 | -$12,633,640 | $40.29 | 315 |
| 2024 Q1 | 74,163,562 | $2,626,695,815 | +$150,901,685 | $35.41 | 290 |
| 2023 Q4 | 70,841,842 | $2,095,507,190 | +$47,113,352 | $29.58 | 264 |
| 2023 Q3 | 69,587,644 | $1,445,242,152 | +$40,169,385 | $20.77 | 224 |
| 2023 Q2 | 67,061,755 | $1,645,737,206 | -$59,226,945 | $24.54 | 242 |
| 2023 Q1 | 68,103,120 | $2,765,613,824 | +$144,781,126 | $40.61 | 270 |
| 2022 Q4 | 64,356,332 | $2,890,283,528 | +$83,553,842 | $44.95 | 290 |
| 2022 Q3 | 62,774,623 | $3,005,075,951 | -$3,660,996 | $47.85 | 279 |
| 2022 Q2 | 61,447,968 | $3,637,020,281 | -$76,699,636 | $59.19 | 317 |
| 2022 Q1 | 59,516,284 | $6,922,056,028 | -$138,240,750 | $116.29 | 365 |
| 2021 Q4 | 60,391,589 | $9,087,447,171 | -$2,104,121 | $150.52 | 376 |
| 2021 Q3 | 61,294,210 | $7,318,019,845 | +$274,585,725 | $119.38 | 331 |
| 2021 Q2 | 59,035,893 | $5,750,025,560 | +$205,481,616 | $97.40 | 295 |
| 2021 Q1 | 57,554,702 | $5,079,400,953 | -$46,897,671 | $88.25 | 282 |
| 2020 Q4 | 58,469,670 | $5,594,436,203 | +$259,885,627 | $95.68 | 295 |
| 2020 Q3 | 54,610,664 | $6,195,906,490 | -$74,521,157 | $113.50 | 317 |
| 2020 Q2 | 55,340,731 | $5,467,195,169 | +$30,463,584 | $98.92 | 298 |
| 2020 Q1 | 55,943,514 | $3,597,678,709 | +$179,201,893 | $64.35 | 272 |