Ionis Pharmaceuticals, Inc.
MX ˙ BMV ˙ US4622221004
SecurityMX:IONS / Ionis Pharmaceuticals, Inc.
InstitutionNorthern Trust Corp
Latest Disclosed Ownership868,179 shares
Latest Disclosed Value $ 65,191,562
Northern Trust Corp reports 2.53% increase in ownership of IONS / Ionis Pharmaceuticals, Inc.

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 868,179 shares of Ionis Pharmaceuticals, Inc. (MX:IONS) valued at $65,191,562 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 846,718 shares of Ionis Pharmaceuticals, Inc.. This represents a change in shares of 2.53% 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)
2026-05-14 2026-03-31 13F IONIS PHARMACEUTICALS COM 462222100 868,179 21,461 2.53 65,192 -2.68 0.0018
2026-02-17 2025-12-31 13F IONIS PHARMACEUTICALS COM 462222100 846,718 1,775 0.21 66,984 21.18 0.0085
2025-11-14 2025-09-30 13F IONIS PHARMACEUTICALS COM 462222100 844,943 30,693 3.77 55,276 71.82 0.0071
2025-08-13 2025-06-30 13F IONIS PHARMACEUTICALS COM 462222100 814,250 -20,597 -2.47 32,171 27.73 0.0044
2025-05-13 2025-03-31 13F IONIS PHARMACEUTICALS COM 462222100 834,847 -5,424 -0.65 25,187 -14.26 0.0037
2025-02-14 2024-12-31 13F IONIS PHARMACEUTICALS COM 462222100 840,271 97,367 13.11 29,376 -1.29 0.0042
2024-11-13 2024-09-30 13F IONIS PHARMACEUTICALS COM 462222100 742,904 24,929 3.47 29,761 -13.03 0.0049
2024-08-14 2024-06-30 13F IONIS PHARMACEUTICALS COM 462222100 717,975 25,728 3.72 34,219 14.03 0.0058
2024-05-14 2024-03-31 13F IONIS PHARMACEUTICALS COM 462222100 692,247 4,261 0.62 30,009 -13.78 0.0052
2024-02-13 2023-12-31 13F IONIS PHARMACEUTICALS COM 462222100 687,986 -2,738 -0.40 34,805 11.09 0.0063
2023-11-13 2023-09-30 13F IONIS PHARMACEUTICALS COM 462222100 690,724 19,646 2.93 31,331 13.79 0.0061
2023-08-11 2023-06-30 13F IONIS PHARMACEUTICALS COM 462222100 671,078 12,612 1.92 27,534 17.00 0.0053
2023-05-15 2023-03-31 13F IONIS PHARMACEUTICALS COM 462222100 658,466 18,777 2.94 23,534 -2.60 0.0047
2023-02-13 2022-12-31 13F IONIS PHARMACEUTICALS COM 462222100 639,689 16,049 2.57 24,161 -12.41 0.0051
2022-11-14 2022-09-30 13F IONIS PHARMACEUTICALS COM 462222100 623,640 -1,832 -0.29 27,583 19.12 0.0063
2022-08-12 2022-06-30 13F IONIS PHARMACEUTICALS COM 462222100 625,472 -23,062 -3.56 23,155 -3.60 0.0050
2022-05-13 2022-03-31 13F IONIS PHARMACEUTICALS COM 462222100 648,534 -12,356 -1.87 24,020 19.43 0.0042
2022-02-08 2021-12-31 13F IONIS PHARMACEUTICALS COM 462222100 660,890 5,469 0.83 20,112 -8.52 0.0033
2021-11-15 2021-09-30 13F IONIS PHARMACEUTICALS COM 462222100 655,421 -16,152 -2.41 21,984 -17.94 0.0039
2021-08-13 2021-06-30 13F IONIS PHARMACEUTICALS COM 462222100 671,573 -169,572 -20.16 26,789 -29.16 0.0047
2021-05-12 2021-03-31 13F IONIS PHARMACEUTICALS COM 462222100 841,145 15,971 1.94 37,818 -18.94 0.0070
2021-02-11 2020-12-31 13F IONIS PHARMACEUTICALS COM 462222100 825,174 -6,362 -0.77 46,656 18.25 0.0091
2020-11-16 2020-09-30 13F IONIS PHARMACEUTICALS COM 462222100 831,536 939 0.11 39,457 -19.43 0.0087
2020-08-14 2020-06-30 13F IONIS PHARMACEUTICALS COM 462222100 830,597 -4,896 -0.59 48,972 23.98 0.0116
2020-05-14 2020-03-31 13F IONIS PHARMACEUTICALS COM 462222100 835,493 37,206 4.66 39,501 -18.09 0.0113
2020-02-14 2019-12-31 13F IONIS PHARMACEUTICALS COM 462222100 798,287 -971 -0.12 48,225 0.71 0.0108
2019-11-13 2019-09-30 13F IONIS PHARMACEUTICALS COM 462222100 799,258 -6,639 -0.82 47,883 -7.55 0.0115
2019-08-13 2019-06-30 13F IONIS PHARMACEUTICALS COM 462222100 805,897 153,326 23.50 51,794 -2.22 0.0123
2019-05-13 2019-03-31 13F IONIS PHARMACEUTICALS COM 462222100 652,571 5,781 0.89 52,969 51.49 0.0131
2019-02-12 2018-12-31 13F IONIS PHARMACEUTICALS COM 462222100 646,790 6,578 1.03 34,966 5.88 0.0098
2018-11-14 2018-09-30 13F IONIS PHARMACEUTICALS COM 462222100 640,212 18,569 2.99 33,023 27.49 0.0081
2018-09-18 2018-06-30 13F/A-1 IONIS PHARMACEUTICALS COM 462222100 621,643 21,286 3.55 25,903 -2.12 0.0066
2018-08-14 2018-06-30 13F IONIS PHARMACEUTICALS COM 462222100 629,802 29,445 26,243
2018-05-09 2018-03-31 13F IONIS PHARMACEUTICALS COM 462222100 600,357 13,375 2.28 26,464 -10.37 0.0069
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS COM 462222100 586,982 -4,396 -0.74 29,525 -1.53 0.0075
2017-11-13 2017-09-30 13F IONIS PHARMACEUTICALS COM 462222100 591,378 -30,438 -4.90 29,983 -5.21 0.0078
2017-08-11 2017-06-30 13F IONIS PHARMACEUTICALS COM 462222100 621,816 44,750 7.75 31,631 36.35 0.0088
2017-05-12 2017-03-31 13F IONIS PHARMACEUTICALS COM 462222100 577,066 65,978 12.91 23,198 -5.10 0.0067
2017-02-13 2016-12-31 13F IONIS PHARMACEUTICALS COM 462222100 511,088 2,604 0.51 24,445 31.21 0.0075
2016-11-09 2016-09-30 13F IONIS PHARMACEUTICALS COM 462222100 508,484 -65,601 -11.43 18,631 39.34 0.0058
2016-08-12 2016-06-30 13F IONIS PHARMACEUTICALS COM 462222100 574,085 24,171 4.40 13,371 -39.96 0.0043
2016-08-19 2016-03-31 13F/A-1 IONIS PHARMACEUTICALS COM 462222100 549,914 10,488 1.94 22,271 -33.33 0.0074
2016-05-13 2016-03-31 13F IONIS PHARMACEUTICALS COM 462222100 549,914 22,271
2016-02-12 2015-12-31 13F Ionis Pharmaceuticals I COMM 462222100 539,426 -87,649 -13.98 33,407 31.80 0.0111
2015-11-12 2015-09-30 13F ISIS PHARMACEUTICALS COM 464330109 627,075 627,075 0.00 25,346 0.0085
2015-08-13 2015-06-30 13F Isis Pharmaceuticals COMM 464330109 0 -1,571,219 -100.00 0 -100.00
2015-05-14 2015-03-31 13F Isis Pharmaceuticals COMM 464330109 1,571,219 224,326 16.66 100,039 20.30 0.0301
2015-02-12 2014-12-31 13F Isis Pharmaceuticals COM 464330109 1,346,893 -32,489 -2.36 83,157 55.26 0.0251
2014-11-13 2014-09-30 13F ISIS PHARMACEUTICALS COM 464330109 1,379,382 22,070 1.63 53,561 14.54 0.0168
2014-08-14 2014-06-30 13F ISIS PHARMACEUTICALS COM 464330109 1,357,312 -165,315 -10.86 46,760 -28.93 0.0146
2014-05-14 2014-03-31 13F ISIS PHARMACEUTICALS COM 464330109 1,522,627 -142,509 -8.56 65,793 -0.82 0.0207
2014-02-21 2013-12-31 13F/A-1 ISIS PHARMACEUTICALS COM 464330109 1,665,136 43,518 2.68 66,338 8.97 0.0213
2014-02-12 2013-12-31 13F ISIS PHARMACEUTICALS COM 464330109 1,665,136 66,338
2013-11-13 2013-09-30 13F ISIS PHARMACEUTICALS COM 464330109 1,621,618 -17,003 -1.04 60,876 38.26 0.0214
2013-08-09 2013-06-30 13F ISIS PHARMACEUTICALS COM 464330109 1,638,621 1,638,621 44,029 0.0160
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.