Jim Simons
TNDM icon

Jim Simons’s Tandem Diabetes Care TNDM Stock Holding History

Jim Simons’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 		$1.12M Buy
+58,227
New +$1.27M ﹤0.01% 2219
2025
Q4 		– Sell
-161,500
Closed -$1.96M – 3763
2025
Q3 		$1.96M Sell
161,500
-180,827
-53% -$2.45M ﹤0.01% 2088
2025
Q2 		$6.38M Buy
342,327
+56,200
+20% +$1.11M 0.01% 1364
2025
Q1 		$5.48M Sell
286,127
-29,600
-9% -$866K 0.01% 1380
2024
Q4 		$11.4M Buy
315,727
+105,300
+50% +$3.56M 0.02% 940
2024
Q3 		$8.92M Sell
210,427
-85,396
-29% -$3.62M 0.01% 1095
2024
Q2 		$11.9M Sell
295,823
-298,504
-50% -$12.5M 0.02% 822
2024
Q1 		$21M Buy
594,327
+576,100
+3,161% +$15.4M 0.03% 616
2023
Q4 		$539K Buy
+18,227
New +$378K ﹤0.01% 2741
2022
Q4 		– Sell
-67,400
Closed -$3.23M – 4420
2022
Q3 		$3.23M Sell
67,400
-85,827
-56% -$4.71M ﹤0.01% 1716
2022
Q2 		$9.07M Buy
153,227
+131,327
+600% +$10.8M 0.01% 1161
2022
Q1 		$2.55M Sell
21,900
-2,327
-10% -$272K ﹤0.01% 2042
2021
Q4 		$3.65M Sell
24,227
-215,319
-90% -$29.1M ﹤0.01% 1724
2021
Q3 		$28.6M Buy
239,546
+205,119
+596% +$22.6M 0.04% 510
2021
Q2 		$3.35M Sell
34,427
-136,700
-80% -$12.2M ﹤0.01% 1894
2021
Q1 		$15.1M Sell
171,127
-145,300
-46% -$13.5M 0.02% 939
2020
Q4 		$30.3M Sell
316,427
-126,669
-29% -$13.1M 0.03% 557
2020
Q3 		$50.3M Sell
443,096
-392,332
-47% -$41.2M 0.05% 376
2020
Q2 		$82.6M Buy
835,428
+340,500
+69% +$27.2M 0.07% 300
2020
Q1 		$31.8M Sell
494,928
-189,972
-28% -$13.3M 0.03% 544
2019
Q4 		$40.8M Sell
684,900
-608,727
-47% -$37.5M 0.03% 619
2019
Q3 		$76.3M Buy
1,293,627
+395,700
+44% +$25.3M 0.06% 365
2019
Q2 		$57.9M Buy
897,927
+123,500
+16% +$7.97M 0.05% 429
2019
Q1 		$49.2M Sell
774,427
-637,900
-45% -$33.5M 0.04% 519
2018
Q4 		$53.6M Buy
1,412,327
+1,016,733
+257% +$35.9M 0.06% 394
2018
Q3 		$16.9M Buy
395,594
+189,230
+92% +$6.61M 0.02% 1037
2018
Q2 		$4.54M Buy
206,364
+49,137
+31% +$604K 0.01% 1844
2018
Q1 		$780K Buy
157,227
+130,377
+486% +$420K ﹤0.01% 2753
2017
Q4 		$63K Buy
26,850
+2,320
+9% +$7.29K ﹤0.01% 3248
2017
Q3 		$179K Buy
24,530
+6,750
+38% +$42.7K ﹤0.01% 3019
2017
Q2 		$142K Buy
17,780
+1,140
+7% +$10.5K ﹤0.01% 3042
2017
Q1 		$200K Sell
16,640
-13,800
-45% -$302K ﹤0.01% 2994
2016
Q4 		$654K Sell
30,440
-5,200
-15% -$200K ﹤0.01% 2687
2016
Q3 		$2.73M Buy
35,640
+6,210
+21% +$453K ﹤0.01% 2007
2016
Q2 		$2.22M Buy
29,430
+5,500
+23% +$443K ﹤0.01% 2140
2016
Q1 		$2.08M Buy
23,930
+7,500
+46% +$656K ﹤0.01% 2193
2015
Q4 		$1.94M Buy
16,430
+2,547
+18% +$253K ﹤0.01% 2133
2015
Q3 		$1.22M Sell
13,883
-8,537
-38% -$994K ﹤0.01% 2273
2015
Q2 		$2.43M Buy
22,420
+13,510
+152% +$1.68M 0.01% 1932
2015
Q1 		$1.12M Buy
+8,910
New +$1.16M ﹤0.01% 2249

Other funds holding TNDM

BlackRock
BlackRock New York $6.73T AUM 46.02% 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 $3.37T AUM 44.26% 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

Jim Simons's TNDM Position: Q1 2026 in Review

Jim Simons opened a new position in Tandem Diabetes Care (TNDM) in Q1 2026: 58,227 shares worth $1.12M. The stake represents ﹤0.01% of the portfolio and ranks #2219 among its holdings. This is a return to the name: Jim Simons previously reported a position in TNDM as recently as Q3 2025.

Jim Simons first reported a position in TNDM in Q1 2015 and has held it in 40 quarters since. The position peaked at $82.6M in Q2 2020. 272 funds tracked by Wall St. Rank hold TNDM as of Q1 2026.

  • Jim Simons held 58,227 shares of Tandem Diabetes Care worth $1.12M as of Q1 2026.
  • Tandem Diabetes Care was a new Jim Simons position in Q1 2026.
  • Tandem Diabetes Care made up ﹤0.01% of Jim Simons's portfolio in Q1 2026, its #2219 holding.
  • Jim Simons first reported a position in Tandem Diabetes Care in Q1 2015 and has held it in 40 quarters since.
  • Jim Simons's Tandem Diabetes Care position peaked at $82.6M in Q2 2020.
  • 272 funds tracked by Wall St. Rank held Tandem Diabetes Care as of Q1 2026.

Based on Renaissance Technologies's 13F filing for Q1 2026, filed 14 May 2026.