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 		$521K Sell
27,200
-90,800
-77% -$1.97M ﹤0.01% 3304
2025
Q4 		$2.59M Sell
118,000
-12,500
-10% -$226K ﹤0.01% 2044
2025
Q3 		$1.58M Buy
130,500
+21,500
+20% +$291K ﹤0.01% 2549
2025
Q2 		$2.03M Buy
109,000
+2,700
+3% +$53.5K ﹤0.01% 2130
2025
Q1 		$2.04M Buy
106,300
+101,600
+2,162% +$2.97M 0.01% 1797
2024
Q4 		$169K Buy
4,700
+800
+21% +$27.1K ﹤0.01% 4072
2024
Q3 		$165K Sell
3,900
-8,400
-68% -$356K ﹤0.01% 3790
2024
Q2 		$496K Buy
12,300
+10,400
+547% +$434K ﹤0.01% 2576
2024
Q1 		$67.3K Sell
1,900
-7,000
-79% -$188K ﹤0.01% 4460
2023
Q4 		$263K Buy
8,900
+6,400
+256% +$133K ﹤0.01% 3614
2023
Q3 		$51.9K Buy
2,500
+400
+19% +$11K ﹤0.01% 5064
2023
Q2 		$51.5K Sell
2,100
-1,900
-48% -$61.1K ﹤0.01% 5250
2023
Q1 		$162K Buy
+4,000
New +$166K ﹤0.01% 3857
2022
Q4 		– Sell
-16,500
Closed -$790K – 8092
2022
Q3 		$790K Buy
16,500
+14,400
+686% +$789K ﹤0.01% 2801
2022
Q2 		$124K Hold
2,100
– – ﹤0.01% 4777
2022
Q1 		$244K Buy
2,100
+1,700
+425% +$198K ﹤0.01% 4589
2021
Q4 		$60K Sell
400
-6,200
-94% -$837K ﹤0.01% 6184
2021
Q3 		$788K Buy
6,600
+800
+14% +$88.1K ﹤0.01% 3674
2021
Q2 		$565K Buy
5,800
+1,200
+26% +$107K ﹤0.01% 4087
2021
Q1 		$406K Sell
4,600
-5,600
-55% -$520K ﹤0.01% 4287
2020
Q4 		$976K Buy
10,200
+1,500
+17% +$155K ﹤0.01% 2665
2020
Q3 		$987K Sell
8,700
-13,300
-60% -$1.4M ﹤0.01% 2206
2020
Q2 		$2.18M Buy
22,000
+12,500
+132% +$997K 0.01% 1411
2020
Q1 		$611K Sell
9,500
-6,200
-39% -$434K 0.01% 1906
2019
Q4 		$936K Sell
15,700
-8,600
-35% -$530K 0.01% 1945
2019
Q3 		$1.43M Sell
24,300
-12,300
-34% -$785K 0.01% 1454
2019
Q2 		$2.36M Buy
36,600
+10,800
+42% +$697K 0.02% 954
2019
Q1 		$1.64M Buy
25,800
+5,200
+25% +$273K 0.02% 1061
2018
Q4 		$782K Sell
20,600
-8,800
-30% -$311K 0.01% 1688
2018
Q3 		$1.26M Buy
29,400
+22,900
+352% +$800K 0.01% 1513
2018
Q2 		$143K Buy
+6,500
New +$79.9K ﹤0.01% 3323
2015
Q2 		– Sell
-200
Closed -$25K – 5179
2015
Q1 		$25K Hold
200
– – ﹤0.01% 3767
2014
Q4 		$25K Sell
200
-1,800
-90% -$250K ﹤0.01% 3835
2014
Q3 		$268K Buy
2,000
+1,900
+1,900% +$266K ﹤0.01% 2143
2014
Q2 		$16K Buy
+100
New +$17K ﹤0.01% 4294

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.