Group One Trading
TNDM icon

Group One Trading’s Tandem Diabetes Care TNDM Stock Holding History

Group One Trading’s Portfolio TNDM Stock Details TNDM Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$109K Buy
5,700
+100
+2% +$2.17K ﹤0.01% 4648
2025
Q4 		$123K Buy
5,600
+1,700
+44% +$30.7K ﹤0.01% 4825
2025
Q3 		$47.3K Sell
3,900
-7,100
-65% -$96.1K ﹤0.01% 6009
2025
Q2 		$205K Buy
11,000
+1,300
+13% +$25.7K ﹤0.01% 4316
2025
Q1 		$186K Buy
9,700
+5,300
+120% +$155K ﹤0.01% 4082
2024
Q4 		$158K Sell
4,400
-4,900
-53% -$166K ﹤0.01% 4120
2024
Q3 		$394K Sell
9,300
-7,000
-43% -$297K ﹤0.01% 3037
2024
Q2 		$657K Buy
16,300
+5,100
+46% +$213K ﹤0.01% 2330
2024
Q1 		$397K Buy
11,200
+4,900
+78% +$131K ﹤0.01% 2957
2023
Q4 		$186K Buy
6,300
+2,600
+70% +$53.9K ﹤0.01% 3929
2023
Q3 		$76.8K Sell
3,700
-4,200
-53% -$115K ﹤0.01% 4699
2023
Q2 		$194K Buy
7,900
+4,500
+132% +$145K ﹤0.01% 3959
2023
Q1 		$138K Sell
3,400
-18,200
-84% -$754K ﹤0.01% 4009
2022
Q4 		$971K Buy
21,600
+4,800
+29% +$217K ﹤0.01% 2436
2022
Q3 		$804K Buy
16,800
+8,500
+102% +$466K ﹤0.01% 2786
2022
Q2 		$491K Sell
8,300
-3,000
-27% -$246K ﹤0.01% 3441
2022
Q1 		$1.31M Sell
11,300
-26,700
-70% -$3.12M ﹤0.01% 2816
2021
Q4 		$5.72M Buy
38,000
+100
+0.3% +$13.5K ﹤0.01% 1579
2021
Q3 		$4.53M Sell
37,900
-25,200
-40% -$2.78M ﹤0.01% 1808
2021
Q2 		$6.15M Sell
63,100
-34,900
-36% -$3.11M 0.01% 1510
2021
Q1 		$8.65M Sell
98,000
-10,600
-10% -$985K 0.01% 1048
2020
Q4 		$10.4M Buy
108,600
+21,900
+25% +$2.26M 0.02% 787
2020
Q3 		$9.84M Sell
86,700
-8,100
-9% -$851K 0.03% 535
2020
Q2 		$9.38M Buy
94,800
+72,300
+321% +$5.77M 0.04% 471
2020
Q1 		$1.45M Sell
22,500
-62,500
-74% -$4.38M 0.01% 1249
2019
Q4 		$5.07M Buy
85,000
+63,700
+299% +$3.93M 0.03% 682
2019
Q3 		$1.26M Sell
21,300
-31,000
-59% -$1.98M 0.01% 1561
2019
Q2 		$3.37M Sell
52,300
-2,800
-5% -$181K 0.03% 742
2019
Q1 		$3.5M Buy
55,100
+21,400
+64% +$1.12M 0.04% 608
2018
Q4 		$1.28M Sell
33,700
-105,800
-76% -$3.74M 0.01% 1329
2018
Q3 		$5.98M Buy
139,500
+58,700
+73% +$2.05M 0.05% 488
2018
Q2 		$1.78M Buy
+80,800
New +$994K 0.02% 1231
2018
Q1 		– Sell
-5,800
Closed -$14K – 5310
2017
Q4 		$14K Buy
+5,800
New +$18.2K ﹤0.01% 4285
2015
Q2 		– Sell
-50
Closed -$6K – 5177
2015
Q1 		$6K Buy
50
+10
+25% +$1.3K ﹤0.01% 4322
2014
Q4 		$5K Sell
40
-130
-76% -$18K ﹤0.01% 4492
2014
Q3 		$23K Buy
+170
New +$23.8K ﹤0.01% 4036

Other funds holding TNDM

BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
SC
Sessa Capital New York $5.51B AUM 47.23% 1-Year Est. Return
VPM
Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM
ACH
ArrowMark Colorado Holdings Denver, Colorado $3.76B AUM 21.77% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
GKIM
GW&K Investment Management Boston, Massachusetts $11.3B AUM 31.98% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
DCM
Driehaus Capital Management Chicago, Illinois $13.6B AUM 173.98% 1-Year Est. Return
Goldman Sachs
Goldman Sachs New York $871B AUM 31.28% 1-Year Est. Return
Citadel Advisors
Citadel Advisors Miami, Florida $618B AUM 30.34% 1-Year Est. Return

Group One Trading's TNDM Position: Q1 2026 in Review

Group One Trading reduced its Tandem Diabetes Care (TNDM) stake by 97% in Q1 2026, selling an estimated $1.28M and leaving 1,815 shares worth $34.8K. The position accounts for ﹤0.01% of the portfolio, ranked #5536.

Group One Trading first reported a position in TNDM in Q3 2014 and has held it in 24 quarters since. The position peaked at $1.72M in Q4 2018. 272 funds tracked by Wall St. Rank hold TNDM as of Q1 2026.

  • Group One Trading held 1,815 shares of Tandem Diabetes Care worth $34.8K as of Q1 2026.
  • Group One Trading sold 58,921 Tandem Diabetes Care shares in Q1 2026, an estimated $1.28M.
  • Tandem Diabetes Care made up ﹤0.01% of Group One Trading's portfolio in Q1 2026, its #5536 holding.
  • Group One Trading first reported a position in Tandem Diabetes Care in Q3 2014 and has held it in 24 quarters since.
  • Group One Trading's Tandem Diabetes Care position peaked at $1.72M in Q4 2018.
  • 272 funds tracked by Wall St. Rank held Tandem Diabetes Care as of Q1 2026.

Based on Group One Trading's 13F filing for Q1 2026, filed 13 May 2026.