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
$21.98
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
75,051,062
Total reported value
$910,952,740
% of total 13F portfolios
0%
Share change
-5,776,778
Value change
-$138,978,063
Number of holders
249
Price from insider filings
$21.98
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% $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
ArrowMark Colorado Holdings LLC 5.5% $44,811,144 3,691,198 ArrowMark Colorado Holdings, LLC 30 Sep 2025

As of 30 Sep 2025, 249 institutional investors reported holding 75,051,062 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 2,062,356 $45,332,236 +$26,765,162 $21.98 28
2025 Q3 75,051,062 $910,952,740 -$138,978,063 $12.14 249
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
2019 Q4 54,323,826 $3,238,388,302 +$215,522,474 $59.61 277
2019 Q3 49,570,173 $2,923,699,368 +$150,187,596 $58.98 265
2019 Q2 46,969,436 $3,030,219,186 +$32,868,289 $64.52 257
2019 Q1 46,852,382 $2,975,069,325 -$42,975,705 $63.50 259
2018 Q4 47,679,245 $1,810,642,238 +$238,092,658 $37.97 197
2018 Q3 41,283,497 $1,768,571,420 +$363,867,902 $42.84 180
2018 Q2 33,358,770 $734,537,970 +$323,358,099 $22.02 114
2018 Q1 21,326,200 $105,775,575 +$86,906,889 $4.96 72
2017 Q4 1,658,886 $3,911,007 -$15,365,244 $2.36 29
2017 Q3 8,179,498 $5,969,000 +$5,969,000 $0.73 4
2016 Q2 0 $0 -$10,000 $21.98 0
2016 Q1 150 $10,000 $66.67 1