Cliff Asness’s Biogen BIIB Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q2 | $417M | Buy |
1,936,859
+13,302
| +0.7% | +$2.54M | 0.15% | 175 |
|
|
2026
Q1 | $346M | Buy |
1,923,557
+394,941
| +26% | +$72.8M | 0.16% | 159 |
|
|
2025
Q4 | $269M | Sell |
1,528,616
-254,965
| -14% | -$41.7M | 0.14% | 183 |
|
|
2025
Q3 | $249M | Buy |
1,783,581
+418,776
| +31% | +$56.6M | 0.16% | 163 |
|
|
2025
Q2 | $171M | Sell |
1,364,805
-4,037
| -0.3% | -$503K | 0.14% | 194 |
|
|
2025
Q1 | $187M | Buy |
1,368,842
+829,150
| +154% | +$119M | 0.19% | 124 |
|
|
2024
Q4 | $81.9M | Buy |
539,692
+489,811
| +982% | +$82.6M | 0.11% | 253 |
|
|
2024
Q3 | $9.62M | Buy |
49,881
+26,324
| +112% | +$5.51M | 0.01% | 817 |
|
|
2024
Q2 | $5.46M | Buy |
23,557
+17,195
| +270% | +$3.74M | 0.01% | 984 |
|
|
2024
Q1 | $1.37M | Sell |
6,362
-30,778
| -83% | -$7.21M | ﹤0.01% | 1563 |
|
|
2023
Q4 | $9.61M | Sell |
37,140
-269,539
| -88% | -$66.2M | 0.02% | 724 |
|
|
2023
Q3 | $78.8M | Sell |
306,679
-29,709
| -9% | -$7.95M | 0.16% | 160 |
|
|
2023
Q2 | $95.7M | Sell |
336,388
-86,098
| -20% | -$25.6M | 0.2% | 112 |
|
|
2023
Q1 | $117M | Buy |
422,486
+224,668
| +114% | +$62.2M | 0.26% | 87 |
|
|
2022
Q4 | $54.4M | Sell |
197,818
-56,640
| -22% | -$16M | 0.12% | 205 |
|
|
2022
Q3 | $65.8M | Sell |
254,458
-258,748
| -50% | -$55M | 0.16% | 150 |
|
|
2022
Q2 | $103M | Buy |
513,206
+116,900
| +29% | +$23.9M | 0.23% | 97 |
|
|
2022
Q1 | $83.5M | Buy |
396,306
+68,085
| +21% | +$14.8M | 0.16% | 145 |
|
|
2021
Q4 | $78.7M | Sell |
328,221
-22,639
| -6% | -$5.82M | 0.14% | 171 |
|
|
2021
Q3 | $99.3M | Sell |
350,860
-163,602
| -32% | -$53.6M | 0.18% | 131 |
|
|
2021
Q2 | $178M | Sell |
514,462
-510,943
| -50% | -$155M | 0.31% | 68 |
|
|
2021
Q1 | $284M | Buy |
1,025,405
+7,983
| +0.8% | +$2.15M | 0.46% | 38 |
|
|
2020
Q4 | $245M | Sell |
1,017,422
-1,199,563
| -54% | -$309M | 0.44% | 43 |
|
|
2020
Q3 | $628M | Sell |
2,216,985
-19,186
| -0.9% | -$5.35M | 1.06% | 11 |
|
|
2020
Q2 | $583M | Buy |
2,236,171
+116,044
| +5% | +$34.9M | 0.94% | 10 |
|
|
2020
Q1 | $661M | Sell |
2,120,127
-516,832
| -20% | -$157M | 1.11% | 11 |
|
|
2019
Q4 | $781M | Sell |
2,636,959
-879,652
| -25% | -$244M | 0.89% | 11 |
|
|
2019
Q3 | $815M | Sell |
3,516,611
-277,141
| -7% | -$64.5M | 0.96% | 8 |
|
|
2019
Q2 | $887M | Sell |
3,793,752
-426,104
| -10% | -$98.4M | 0.99% | 11 |
|
|
2019
Q1 | $992M | Buy |
4,219,856
+1,063,775
| +34% | +$335M | 1.05% | 8 |
|
|
2018
Q4 | $950M | Buy |
3,156,081
+132,044
| +4% | +$42.1M | 1.1% | 5 |
|
|
2018
Q3 | $1.07B | Buy |
3,024,037
+183,542
| +6% | +$63.2M | 1.02% | 10 |
|
|
2018
Q2 | $824M | Buy |
2,840,495
+396,445
| +16% | +$111M | 0.83% | 14 |
|
|
2018
Q1 | $669M | Buy |
2,444,050
+477,916
| +24% | +$148M | 0.72% | 23 |
|
|
2017
Q4 | $626M | Buy |
1,966,134
+96,473
| +5% | +$30.9M | 0.66% | 27 |
|
|
2017
Q3 | $585M | Buy |
1,869,661
+565,002
| +43% | +$167M | 0.7% | 21 |
|
|
2017
Q2 | $354M | Buy |
1,304,659
+264,040
| +25% | +$69.8M | 0.47% | 41 |
|
|
2017
Q1 | $285M | Buy |
1,040,619
+368,587
| +55% | +$104M | 0.38% | 58 |
|
|
2016
Q4 | $191M | Sell |
672,032
-50,572
| -7% | -$15M | 0.26% | 88 |
|
|
2016
Q3 | $226M | Buy |
722,604
+377,752
| +110% | +$112M | 0.35% | 62 |
|
|
2016
Q2 | $83.4M | Buy |
344,852
+57,156
| +20% | +$15.1M | 0.15% | 197 |
|
|
2016
Q1 | $74.9M | Sell |
287,696
-525,397
| -65% | -$139M | 0.13% | 214 |
|
|
2015
Q4 | $249M | Sell |
813,093
-167,066
| -17% | -$48M | 0.44% | 39 |
|
|
2015
Q3 | $286M | Sell |
980,159
-16,285
| -2% | -$5.38M | 0.57% | 32 |
|
|
2015
Q2 | $403M | Buy |
996,444
+162,199
| +19% | +$65.1M | 0.8% | 12 |
|
|
2015
Q1 | $352M | Sell |
834,245
-367,044
| -31% | -$145M | 0.81% | 10 |
|
|
2014
Q4 | $408M | Buy |
1,201,289
+93,290
| +8% | +$30.2M | 0.85% | 7 |
|
|
2014
Q3 | $367M | Buy |
1,107,999
+316,275
| +40% | +$104M | 1.01% | 3 |
|
|
2014
Q2 | $250M | Buy |
791,724
+64,600
| +9% | +$19.4M | 0.67% | 12 |
|
|
2014
Q1 | $222M | Buy |
727,124
+129,500
| +22% | +$41.1M | 0.67% | 13 |
|
|
2013
Q4 | $167M | Buy |
597,624
+213,992
| +56% | +$55.3M | 0.5% | 30 |
|
|
2013
Q3 | $92.4M | Sell |
383,632
-42,976
| -10% | -$9.62M | 0.33% | 60 |
|
|
2013
Q2 | $91.8M | Buy |
+426,608
| New | +$91.2M | 0.33% | 59 |
|
Other funds holding BIIB
Cliff Asness's BIIB Position: Q2 2026 in Review
Cliff Asness increased its Biogen (BIIB) stake by 0.69% in Q2 2026, buying an estimated $2.54M and bringing the position to 1,936,859 shares worth $417M. The position accounts for 0.15% of the portfolio, ranked #175.
Cliff Asness first reported a position in BIIB in Q2 2013 and has held it in 53 quarters since. The position peaked at $1.07B in Q3 2018. 1,036 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.
- Cliff Asness held 1,936,859 shares of Biogen worth $417M as of Q2 2026.
- Cliff Asness bought 13,302 Biogen shares in Q2 2026, an estimated $2.54M.
- Biogen made up 0.15% of Cliff Asness's portfolio in Q2 2026, its #175 holding.
- Cliff Asness first reported a position in Biogen in Q2 2013 and has held it in 53 quarters since.
- Cliff Asness's Biogen position peaked at $1.07B in Q3 2018.
- 1,036 funds tracked by Wall St. Rank held Biogen as of Q2 2026.
Based on AQR Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.