Renaissance Technologies's BIIB Position Overview
Renaissance Technologies (via Renaissance Technologies LLC) currently holds 399,196 shares of Biogen Inc. (BIIB) worth $70.25 M, representing 0.11% of the portfolio. First purchased in 2013-Q2, this long-term strategic position has been held for 51 quarters.
Based on 13F filings since 2013, Renaissance Technologies has maintained a long-term strategic position in BIIB, representing a significant commitment to this investment thesis. Largest addition occurred in Q3 2019, adding 1.74 M shares. Largest reduction occurred in Q1 2021, reducing 1.1 M shares.
Analysis based on 13F filings available since 2013 Q2
Renaissance Technologies's Biogen (BIIB) Holding Value Over Time
Track share changes against reported price movement
Quarterly Biogen (BIIB) Trades by Renaissance Technologies
| Report Date | Bought/Sold (Sh.) | % Change | Qtr. End Shares | Reported Price |
|---|---|---|---|---|
| Q4 2025 | -565,210 | Reduce 58.61% | 399,196 | $175.99 |
| Q3 2025 | -80,700 | Reduce 7.72% | 964,406 | $140.08 |
| Q2 2025 | +240,600 | Add 29.91% | 1.05 M | $125.59 |
| Q1 2025 | -387,700 | Reduce 32.52% | 804,506 | $136.84 |
| Q4 2024 | +239,500 | Add 25.14% | 1.19 M | $152.92 |
| Q3 2024 | +334,600 | Add 54.13% | 952,706 | $193.84 |
| Q2 2024 | -266,598 | Reduce 30.13% | 618,106 | $231.82 |
| Q1 2024 | +126,098 | Add 16.62% | 884,704 | $215.63 |
| Q4 2023 | -327,791 | Reduce 30.17% | 758,606 | $258.77 |
| Q3 2023 | -23,140 | Reduce 2.09% | 1.09 M | $257.01 |
| Q2 2023 | -154,300 | Reduce 12.21% | 1.11 M | $0.28 |
| Q1 2023 | +263,561 | Add 26.35% | 1.26 M | $0.28 |
| Q4 2022 | -154,231 | Reduce 13.36% | 1 M | $0.28 |
| Q3 2022 | -391,500 | Reduce 25.32% | 1.15 M | $267.00 |
| Q2 2022 | +501,800 | Add 48.06% | 1.55 M | $203.94 |
| Q1 2022 | -29,600 | Reduce 2.76% | 1.04 M | $210.60 |
| Q4 2021 | +92,100 | Add 9.38% | 1.07 M | $239.92 |
| Q3 2021 | -348,296 | Reduce 26.19% | 981,707 | $282.99 |
| Q2 2021 | -608,159 | Reduce 31.38% | 1.33 M | $346.27 |
| Q1 2021 | -1.1 M | Reduce 36.20% | 1.94 M | $279.75 |
| Q4 2020 | -779,199 | Reduce 20.41% | 3.04 M | $244.86 |
| Q3 2020 | -88,961 | Reduce 2.28% | 3.82 M | $283.68 |
| Q2 2020 | -567,990 | Reduce 12.70% | 3.91 M | $267.55 |
| Q1 2020 | -95,994 | Reduce 2.10% | 4.47 M | $316.38 |
| Q4 2019 | +348,700 | Add 8.26% | 4.57 M | $296.73 |
| Q3 2019 | +1.74 M | Add 70.00% | 4.22 M | $232.82 |
| Q2 2019 | +851,263 | Add 52.17% | 2.48 M | $233.87 |
| Q1 2019 | +617,100 | Add 60.82% | 1.63 M | $236.38 |
| Q4 2018 | +168,639 | Add 19.93% | 1.01 M | $300.92 |
| Q3 2018 | +524,575 | Add 163.16% | 846,075 | $353.31 |
| Q2 2018 | -306,161 | Reduce 48.78% | 321,500 | $290.24 |
| Q1 2018 | +627,661 | New Buy | 627,661 | $273.82 |
| Q4 2017 | -120,161 | Sold Out | 0 | $0.00 |
| Q3 2017 | -642,700 | Reduce 84.25% | 120,161 | $313.12 |
| Q2 2017 | -86,100 | Reduce 10.14% | 762,861 | $271.36 |
| Q1 2017 | +141,466 | Add 20.00% | 848,961 | $273.42 |
| Q4 2016 | +469,234 | Add 196.94% | 707,495 | $283.58 |
| Q3 2016 | +197,861 | Add 489.75% | 238,261 | $313.03 |
| Q2 2016 | -87,261 | Reduce 68.35% | 40,400 | $241.83 |
| Q1 2016 | +127,661 | New Buy | 127,661 | $260.32 |
| Q4 2015 | -34,961 | Sold Out | 0 | $0.00 |
| Q3 2015 | -70,300 | Reduce 66.79% | 34,961 | $291.81 |
| Q2 2015 | +74,961 | Add 247.40% | 105,261 | $403.94 |
| Q1 2015 | -34,861 | Reduce 53.50% | 30,300 | $422.24 |
| Q4 2014 | -27,500 | Reduce 29.68% | 65,161 | $339.45 |
| Q3 2014 | -36,600 | Reduce 28.31% | 92,661 | $330.81 |
| Q2 2014 | +129,261 | New Buy | 129,261 | $315.31 |
| Q1 2014 | -542,338 | Sold Out | 0 | $0.00 |
| Q4 2013 | -327,362 | Reduce 37.64% | 542,338 | $279.57 |
| Q3 2013 | -523,800 | Reduce 37.59% | 869,700 | $240.76 |
| Q2 2013 | +1.39 M | Add 0.00% | 1.39 M | $215.20 |
Renaissance Technologies's Biogen Investment FAQs
Renaissance Technologies first purchased Biogen Inc. (BIIB) in Q2 2013, acquiring 1,393,500 shares, as reported in their 13F filing for that period. Note: Analysis reflects filings available since Q2 2013; earlier records may be incomplete.
Renaissance Technologies has held Biogen Inc. (BIIB) for 51 quarters since Q2 2013.
Renaissance Technologies's largest addition to Biogen Inc. (BIIB) was in Q3 2019, adding 4,221,206 shares worth $982.78 M.
According to the latest 13F filing for Q4 2025, Renaissance Technologies's firm, Renaissance Technologies LLC, owns 399,196 shares of Biogen Inc. (BIIB), valued at approximately $70.25 M.
As of the Q4 2025 filing, Biogen Inc. (BIIB) represents approximately 0.11% of Renaissance Technologies's publicly disclosed stock portfolio, making it one of their key holdings.
Renaissance Technologies's peak holding in Biogen Inc. (BIIB) was 4,569,906 shares, as reported at the end of Q4 2019.