Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionMackenzie Financial Corp
Latest Disclosed Ownership71,432 shares
Latest Disclosed Value $ 13,095,629
Mackenzie Financial Corp reports 0.50% increase in ownership of BIIB / Biogen Inc.

On May 13, 2026 - Mackenzie Financial Corp filed a 13F-HR form disclosing ownership of 71,432 shares of Biogen Inc. (MX:BIIB) valued at $13,095,629 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 18, 2026 disclosing 71,075 shares of Biogen Inc.. This represents a change in shares of 0.50% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-13 2026-03-31 13F BIOGEN COM 09062X103 71,432 357 0.50 13,096 4.66 0.0157
2026-02-18 2025-12-31 13F BIOGEN COM 09062X103 71,075 7,321 11.48 12,513 40.11 0.0148
2025-11-13 2025-09-30 13F BIOGEN COM 09062X103 63,754 -18,582 -22.57 8,931 -13.64 0.0108
2025-08-13 2025-06-30 13F BIOGEN COM 09062X103 82,336 35,652 76.37 10,341 61.87 0.0134
2025-05-07 2025-03-31 13F BIOGEN COM 09062X103 46,684 12,838 37.93 6,388 23.44 0.0091
2025-05-02 2024-12-31 13F/A-2 BIOGEN COM 09062X103 33,846 19,759 140.26 5,176 89.56 0.0071
2025-02-20 2024-12-31 13F/A-1 BIOGEN COM 09062X103 33,846 19,759 5,176 0.0067
2025-02-14 2024-12-31 13F Biogen Common Stock 09062X103 33,846 19,759 4,976 0.0071
2024-11-13 2024-09-30 13F BIOGEN COM 09062X103 14,087 -11,577 -45.11 2,731 -54.11 0.0038
2024-08-14 2024-06-30 13F BIOGEN COM 09062X103 25,664 -21,558 -45.65 5,949 -41.57 0.0088
2024-05-10 2024-03-31 13F BIOGEN COM 09062X103 47,222 -13,404 -22.11 10,182 -35.10 0.0147
2024-01-30 2023-12-31 13F BIOGEN COM 09062X103 60,626 13,796 29.46 15,688 33.31 0.0237
2023-10-25 2023-09-30 13F BIOGEN COM 09062X103 46,830 4,209 9.88 11,769 -3.26 0.0198
2023-08-03 2023-06-30 13F BIOGEN COM 09062X103 42,621 -2,968 -6.51 12,166 -4.02 0.0185
2023-04-24 2023-03-31 13F BIOGEN COM 09062X103 45,589 -474 -1.03 12,675 -0.63 0.0196
2023-02-14 2022-12-31 13F BIOGEN COM 09062X103 46,063 -7,491 -13.99 12,756 -10.80 0.0213
2022-10-07 2022-09-30 13F Biogen Common Stock 09062X103 53,554 -11,486 -17.66 14,299 7.80 0.0246
2022-08-10 2022-06-30 13F BIOGEN COM 09062X103 65,040 20,338 45.50 13,264 40.90 0.0212
2022-05-13 2022-03-31 13F BIOGEN COM 09062X103 44,702 197 0.44 9,414 -11.84 0.0126
2022-02-14 2021-12-31 13F BIOGEN COM 09062X103 44,505 4,691 11.78 10,678 -5.23 0.0144
2021-11-08 2021-09-30 13F BIOGEN COM 09062X103 39,814 -6,627 -14.27 11,267 -29.94 0.0160
2021-08-11 2021-06-30 13F BIOGEN COM 09062X103 46,441 -1,128 -2.37 16,081 20.85 0.0224
2021-05-14 2021-03-31 13F BIOGEN COM 09062X103 47,569 -30,622 -39.16 13,307 -30.50 0.0203
2021-02-10 2020-12-31 13F BIOGEN COM 09062X103 78,191 2,489 3.29 19,146 -10.85 0.0413
2020-11-13 2020-09-30 13F BIOGEN COM 09062X103 75,702 -4,716 -5.86 21,475 -0.19 0.0533
2020-08-13 2020-06-30 13F BIOGEN COM 09062X103 80,418 60,611 306.01 21,516 243.32 0.0576
2020-05-14 2020-03-31 13F BIOGEN COM 09062X103 19,807 -6,311 -24.16 6,267 -19.14 0.0202
2020-02-13 2019-12-31 13F BIOGEN COM 09062X103 26,118 -4,324 -14.20 7,750 9.34 0.0191
2019-11-14 2019-09-30 13F BIOGEN COM 09062X103 30,442 630 2.11 7,088 1.66 0.0186
2019-08-23 2019-06-30 13F/A-1 BIOGEN COM 09062X103 29,812 -7,928 -21.01 6,972 -21.85 0.0180
2019-08-14 2019-06-30 13F BIOGEN COM 09062X103 29,812 -7,928 6,972
2019-05-15 2019-03-31 13F BIOGEN COM 09062X103 37,740 -361,413 -90.54 8,921 -92.57 0.0215
2019-02-06 2018-12-31 13F BIOGEN COM 09062X103 399,153 69,178 20.96 120,113 3.03 0.3158
2018-11-15 2018-09-30 13F BIOGEN COM 09062X103 329,975 295,060 845.08 116,583 1,050.41 0.2836
2018-08-13 2018-06-30 13F BIOGEN COM 09062X103 34,915 832 2.44 10,134 8.58 0.0259
2018-05-14 2018-03-31 13F/A-1 BIOGEN COM 09062X103 34,083 -30,461 -47.19 9,333 -54.61 0.0238
2018-05-14 2018-03-31 13F BIOGEN COM 09062X103 34,083 9,333
2018-02-13 2017-12-31 13F BIOGEN COM 09062X103 64,544 64,544 20,562 0.0496
2016-11-15 2016-09-30 13F BIOGEN COM 09062X103 0 -8,636 -100.00 0 -100.00
2016-08-12 2016-06-30 13F BIOGEN COM 09062X103 8,636 -534 -5.82 2,088 -12.53 0.0118
2016-05-12 2016-03-31 13F BIOGEN COM 09062X103 9,170 1,790 24.25 2,387 5.57 0.0217
2016-02-12 2015-12-31 13F BIOGEN COM 09062X103 7,380 -2,210 -23.04 2,261 -19.19 0.0140
2015-11-13 2015-09-30 13F BIOGEN COM 09062X103 9,590 -22,630 -70.24 2,798 -78.50 0.0170
2015-08-13 2015-06-30 13F BIOGEN COM 09062X103 32,220 -13,555 -29.61 13,015 -32.66 0.0706
2015-05-13 2015-03-31 13F BIOGEN COM 09062X103 45,775 -7,655 -14.33 19,328 6.57 0.1019
2015-02-11 2014-12-31 13F BIOGEN IDEC COM 09062X103 53,430 -24,110 -31.09 18,137 -29.29 0.0925
2014-11-12 2014-09-30 13F BIOGEN IDEC COM 09062X103 77,540 -26,005 -25.11 25,651 -21.43 0.1286
2014-08-11 2014-06-30 13F BIOGEN IDEC COM 09062X103 103,545 -7,280 -6.57 32,649 -3.68 0.1519
2014-05-14 2014-03-31 13F BIOGEN IDEC COM 09062X103 110,825 10,210 10.15 33,898 20.51 0.1662
2014-02-11 2013-12-31 13F/A-1 BIOGEN IDEC COM 09062X103 100,615 7,207 7.72 28,129 25.08 0.1421
2014-02-03 2013-12-31 13F BIOGEN IDEC COM 09062X103 100,615 28,129
2013-11-12 2013-09-30 13F BIOGEN IDEC COM 09062X103 93,408 4,066 4.55 22,489 16.97 0.1138
2013-08-20 2013-06-30 13F/A-1 BIOGEN IDEC COM 09062X103 89,342 89,342 19,226 0.0917
2013-08-09 2013-06-30 13F BIOGEN IDEC COM 09062X103 89,342 19,226 0.0920
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.