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 31 Dec 2025
Q4 2025
Total 13F shares
50,101,098
Total reported value
$1,101,218,244
% of total 13F portfolios
0%
Share change
+930,392
Value change
+$33,868,123
Number of holders
193
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% $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 31 Dec 2025, 193 institutional investors reported holding 50,101,098 shares of TANDEM DIABETES CARE INC - Common Stock, par value $0.001 per share (TNDM). This represents 74% 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 66% 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. 16% 11,149,181 -7.9% 0% $245,058,999
VANGUARD GROUP INC 11% 7,341,356 +3.9% 0% $161,363,004
GW&K Investment Management, LLC 4% 2,675,157 -1.7% 0.51% $58,800,000
STATE STREET CORP 3.9% 2,641,724 -0.99% 0% $58,065,094
MORGAN STANLEY 3.1% 2,080,497 +182% 0% $45,729,350
Paradice Investment Management LLC 3.1% 2,077,745 -5.4% 8.9% $45,668,835
JENNISON ASSOCIATES LLC 3% 2,021,376 +42% 0.03% $44,429,844
GOLDMAN SACHS GROUP INC 2.5% 1,683,400 +18% 0.01% $37,001,133
JACOBS LEVY EQUITY MANAGEMENT, INC 2.4% 1,653,708 +12% 0.14% $36,348,502
GEODE CAPITAL MANAGEMENT, LLC 2.4% 1,649,383 +3.2% 0% $36,259,526
BNP PARIBAS FINANCIAL MARKETS 1.8% 1,248,481 0% 0.02% $27,441,612
Assenagon Asset Management S.A. 1.8% 1,227,856 0.04% $26,988,275
BAILLIE GIFFORD & CO 1.7% 1,145,516 +2.2% 0.02% $25,178,442
BARCLAYS PLC 1.4% 917,927 -23% 0.01% $20,176,036
MARSHALL WACE, LLP 1.3% 875,531 0.02% $19,244,172
ROYCE & ASSOCIATES LP 0.96% 650,250 +28% 0.14% $14,292,495
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.96% 646,310 +16% 0% $14,205,894
Nuveen, LLC 0.83% 563,274 +12% 0% $12,380,763
Aberdeen Group plc 0.81% 547,035 -8.5% 0.02% $12,023,829
UBS Group AG 0.62% 417,833 -72% 0% $9,183,970
ACADIAN ASSET MANAGEMENT LLC 0.58% 392,763 -57% 0.01% $8,625,000
Bank of New York Mellon Corp 0.52% 349,753 -9% 0% $7,687,577
JPMORGAN CHASE & CO 0.51% 341,631 -4.9% 0% $7,509,049
PRINCIPAL FINANCIAL GROUP INC 0.48% 324,262 -0.75% 0% $7,127,279
VOYA INVESTMENT MANAGEMENT LLC 0.47% 319,528 +83% 0.01% $7,023,225

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 50,101,098 $1,101,218,244 +$33,868,123 $21.98 193
2025 Q3 75,051,127 $910,953,529 -$138,715,065 $12.14 250
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 $21.55 0
2016 Q1 150 $10,000 $66.67 1