Jim Simons
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Jim Simons’s Atara Biotherapeutics ATRA Stock Holding History

Jim Simons’s Portfolio ATRA Stock Details ATRA Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		– Sell
-30,040
Closed -$543K – 3247
2025
Q4 		$543K Buy
30,040
+11,104
+59% +$166K ﹤0.01% 2546
2025
Q3 		$271K Buy
18,936
+2,000
+12% +$23K ﹤0.01% 3042
2025
Q2 		$131K Sell
16,936
-500
-3% -$3.65K ﹤0.01% 3257
2025
Q1 		$104K Sell
17,436
-49,704
-74% -$434K ﹤0.01% 3195
2024
Q4 		$894K Sell
67,140
-594
-0.9% -$6.26K ﹤0.01% 2557
2024
Q3 		$551K Buy
67,734
+21,670
+47% +$186K ﹤0.01% 2744
2024
Q2 		$392K Buy
46,064
+6,849
+17% +$103K ﹤0.01% 2800
2024
Q1 		$680K Buy
39,215
+14,299
+57% +$254K ﹤0.01% 2721
2023
Q4 		$319K Sell
24,916
-8,248
-25% -$192K ﹤0.01% 2964
2023
Q3 		$1.23M Sell
33,164
-51,512
-61% -$2.29M ﹤0.01% 2162
2023
Q2 		$3.41M Buy
84,676
+27,168
+47% +$1.54M ﹤0.01% 1651
2023
Q1 		$4.17M Buy
57,508
+50,908
+771% +$4.94M 0.01% 1582
2022
Q4 		$541K Sell
6,600
-6,844
-51% -$713K ﹤0.01% 2913
2022
Q3 		$1.27M Buy
13,444
+4,436
+49% +$498K ﹤0.01% 2353
2022
Q2 		$1.75M Sell
9,008
-13,784
-60% -$2.25M ﹤0.01% 2288
2022
Q1 		$5.29M Buy
+22,792
New +$7.26M 0.01% 1552
2021
Q4 		– Sell
-11,267
Closed -$5.04M – 3886
2021
Q3 		$5.04M Sell
11,267
-24,681
-69% -$8.84M 0.01% 1459
2021
Q2 		$14M Buy
35,948
+14,904
+71% +$5.32M 0.02% 961
2021
Q1 		$7.55M Buy
21,044
+20,220
+2,454% +$8.94M 0.01% 1374
2020
Q4 		$404K Buy
+824
New +$380K ﹤0.01% 2915
2020
Q2 		– Sell
-1,024
Closed -$218K – 3425
2020
Q1 		$218K Buy
+1,024
New +$325K ﹤0.01% 3079
2019
Q3 		– Sell
-6,086
Closed -$3.06M – 3419
2019
Q2 		$3.06M Buy
+6,086
New +$4.3M ﹤0.01% 2108

Other funds holding ATRA

Adage Capital Partners
Adage Capital Partners Boston, Massachusetts $64.8B AUM 42.7% 1-Year Est. Return
RG
Redmile Group San Francisco, California $1.51B AUM 164.17% 1-Year Est. Return
Mackenzie Financial
Mackenzie Financial Toronto Ontario, Ontario, Canada $83.3B AUM 31.19% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
Point72 Asset Management
Point72 Asset Management Stamford, Connecticut $78.1B AUM 55.25% 1-Year Est. Return
Acadian Asset Management
Acadian Asset Management Boston, Massachusetts $70.5B AUM 36% 1-Year Est. Return
EC
EcoR1 Capital San Francisco, California $2.36B AUM 204.53% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $666B AUM 30.12% 1-Year Est. Return

Jim Simons's ATRA Position: Q1 2026 in Review

Jim Simons sold out of Atara Biotherapeutics (ATRA) in Q1 2026, closing a stake of 30,040 shares — an estimated $543K sold.

Jim Simons first reported a position in ATRA in Q2 2019 and held it in 22 quarters. The position peaked at $14M in Q2 2021. 33 funds tracked by Wall St. Rank hold ATRA as of Q1 2026.

  • Jim Simons reported no remaining Atara Biotherapeutics position as of Q1 2026 after selling out during the quarter.
  • Jim Simons sold 30,040 Atara Biotherapeutics shares in Q1 2026, an estimated $543K.
  • Jim Simons first reported a position in Atara Biotherapeutics in Q2 2019 and held it in 22 quarters.
  • Jim Simons's Atara Biotherapeutics position peaked at $14M in Q2 2021.
  • 33 funds tracked by Wall St. Rank held Atara Biotherapeutics as of Q1 2026.

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