TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM) Institutional Ownership

13F Institutional Holders and Ownership History from Q1 2016 to Q4 2025

Type / Class
Equity / Common Stock, par value $0.001 per share
Symbol
TNDM on Nasdaq
Shares outstanding
67,604,359
Price per share
$21.55
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
75,051,127
Total reported value
$910,953,529
% of total 13F portfolios
0%
Share change
-5,776,713
Value change
-$138,977,291
Number of holders
250
Price from insider filings
$21.55
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
BlackRock, Inc. 15% $189,298,154 10,106,682 BlackRock, Inc. 31 Mar 2025
Sessa Capital (Master), L.P. 6.7% $83,653,930 4,466,307 Sessa Capital (Master), L.P. 31 Mar 2025
ArrowMark Colorado Holdings LLC 5.5% $44,811,144 3,691,198 ArrowMark Colorado Holdings, LLC 30 Sep 2025

As of 30 Sep 2025, 250 institutional investors reported holding 75,051,127 shares of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM). This represents 111% of the company’s total 67,604,359 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM) together control 85% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
BlackRock, Inc. 18% 12,101,471 +11% 0% $146,911,857
VANGUARD GROUP INC 10% 7,063,314 -4.2% 0% $85,748,632
Sessa Capital IM, L.P. 7.4% 5,000,000 0% 1.5% $60,700,000
ArrowMark Colorado Holdings LLC 5.5% 3,691,198 +37% 0.83% $44,811,144
GW&K Investment Management, LLC 4% 2,721,649 -5.8% 0.29% $33,041,000
STATE STREET CORP 3.9% 2,668,188 +0.84% 0% $32,391,802
Hood River Capital Management LLC 3.8% 2,551,644 -0.52% 0.37% $30,976,958
Paradice Investment Management LLC 3.2% 2,196,468 +24% 6% $26,665,122
Freestone Grove Partners LP 2.8% 1,870,307 0.17% $22,705,527
GEODE CAPITAL MANAGEMENT, LLC 2.4% 1,598,281 -0.5% 0% $19,406,140
UBS Group AG 2.2% 1,504,377 +8.7% 0% $18,263,137
JACOBS LEVY EQUITY MANAGEMENT, INC 2.2% 1,481,953 +3.5% 0.07% $17,990,909
GOLDMAN SACHS GROUP INC 2.1% 1,431,372 -24% 0% $17,376,856
JENNISON ASSOCIATES LLC 2.1% 1,420,116 -14% 0.01% $17,240,209
BARCLAYS PLC 1.8% 1,190,127 +110% 0.01% $14,448,141
BAILLIE GIFFORD & CO 1.7% 1,120,595 -0.46% 0.01% $13,604,022
TWO SIGMA INVESTMENTS, LP 1.7% 1,117,202 -9.4% 0.02% $13,562,832
TWO SIGMA ADVISERS, LP 1.4% 970,883 +9.3% 0.02% $11,786,520
ACADIAN ASSET MANAGEMENT LLC 1.4% 918,723 +156% 0.02% $11,143,000
D. E. Shaw & Co., Inc. 1.3% 877,217 +159% 0.01% $10,649,415
FMR LLC 1.3% 870,123 +66% 0% $10,563,290
MORGAN STANLEY 1.1% 737,547 -42% 0% $8,953,819
MILLENNIUM MANAGEMENT LLC 1% 705,902 -27% 0.01% $8,569,650
NORTHERN TRUST CORP 1% 690,883 -1.4% 0% $8,387,319
ROYAL BANK OF CANADA 1% 681,078 +24% 0% $8,267,000

Institutional Holders of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 27,167,484 $597,136,969 +$11,191,205 $21.98 125
2025 Q3 75,051,127 $910,953,529 -$138,977,291 $12.14 250
2025 Q2 80,970,548 $1,506,919,626 +$146,515,995 $18.64 269
2025 Q1 73,028,420 $1,399,470,835 -$74,262,836 $19.16 271
2024 Q4 72,055,654 $2,595,672,681 -$53,962,719 $36.02 310
2024 Q3 73,021,357 $3,096,468,612 -$23,192,746 $42.41 328
2024 Q2 73,578,810 $2,964,480,926 -$12,248,187 $40.29 316
2024 Q1 74,108,051 $2,624,730,564 +$131,293,050 $35.41 291
2023 Q4 82,071 $2,427,661 -$4,686,240 $29.58 4
2023 Q3 68,604,041 $1,424,813,666 +$36,713,717 $20.77 219
2023 Q2 65,970,236 $1,618,951,615 -$79,753,480 $24.54 238
2023 Q1 68,061,605 $2,763,927,916 +$143,728,387 $40.61 269
2022 Q4 64,039,561 $2,876,045,402 +$82,010,320 $44.95 285
2022 Q3 61,876,672 $2,962,109,408 +$41,580,342 $47.85 275
2022 Q2 61,440,854 $3,631,346,540 -$76,961,426 $59.19 316
2022 Q1 59,474,718 $6,917,223,028 -$142,481,505 $116.29 362
2021 Q4 60,391,580 $9,087,445,418 +$31,910,039 $150.52 374
2021 Q3 61,173,561 $7,303,611,966 +$274,597,654 $119.38 329
2021 Q2 59,029,940 $5,749,446,132 +$205,338,228 $97.40 296
2021 Q1 57,554,522 $5,079,384,953 -$45,563,167 $88.25 284
2020 Q4 58,446,117 $5,592,182,203 +$257,661,607 $95.68 292
2020 Q3 54,610,595 $6,195,898,490 -$68,358,586 $113.50 316
2020 Q2 55,340,731 $5,467,195,169 +$14,428,332 $98.92 298
2020 Q1 55,801,784 $3,588,559,709 +$178,779,574 $64.35 268
2019 Q4 54,258,561 $3,234,258,419 +$216,540,058 $59.61 271
2019 Q3 49,424,226 $2,915,087,053 +$145,761,689 $58.98 259
2019 Q2 46,942,713 $3,028,497,063 +$63,874,355 $64.52 254
2019 Q1 46,835,406 $2,973,985,975 -$41,859,808 $63.50 257
2018 Q4 47,307,434 $1,796,524,441 +$232,550,211 $37.97 193
2018 Q3 40,642,206 $1,741,098,136 +$355,226,453 $42.84 178
2018 Q2 33,358,640 $734,533,970 +$323,342,505 $22.02 113
2018 Q1 19,027,092 $94,372,575 +$86,617,130 $4.96 70
2017 Q4 1,551,345 $3,658,007 -$15,615,180 $2.36 27
2017 Q3 8,179,498 $5,969,000 +$5,969,013 $0.73 4
2016 Q1 150 $10,000 $0 $66.67 1