Ionis Pharmaceuticals, Inc.
MX ˙ BMV ˙ US4622221004
SecurityMX:IONS / Ionis Pharmaceuticals, Inc.
InstitutionStifel Financial Corp
Latest Disclosed Ownership196,703 shares
Latest Disclosed Value $ 14,770,441
Stifel Financial Corp reports 1.09% decrease in ownership of IONS / Ionis Pharmaceuticals, Inc.

On May 12, 2026 - Stifel Financial Corp filed a 13F-HR form disclosing ownership of 196,703 shares of Ionis Pharmaceuticals, Inc. (MX:IONS) valued at $14,770,441 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 198,863 shares of Ionis Pharmaceuticals, Inc.. This represents a change in shares of -1.09% 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)
2026-05-12 2026-03-31 13F IONIS PHARMACEUTICALS COM 462222100 196,703 -2,160 -1.09 14,770 -6.11 0.0032
2026-02-13 2025-12-31 13F IONIS PHARMACEUTICALS COM 462222100 198,863 -3,765 -1.86 15,732 18.69 0.0142
2025-11-12 2025-09-30 13F IONIS PHARMACEUTICALS COM 462222100 202,628 6,271 3.19 13,256 70.86 0.0121
2025-08-14 2025-06-30 13F IONIS PHARMACEUTICALS COM 462222100 196,357 -4,585 -2.28 7,758 27.98 0.0075
2025-05-14 2025-03-31 13F IONIS PHARMACEUTICALS COM 462222100 200,942 -10,551 -4.99 6,062 -18.00 0.0064
2025-02-13 2024-12-31 13F IONIS PHARMACEUTICALS COM 462222100 211,493 28,988 15.88 7,394 1.12 0.0077
2024-11-14 2024-09-30 13F IONIS PHARMACEUTICALS COM 462222100 182,505 -33,635 -15.56 7,311 -29.03 0.0077
2024-08-13 2024-06-30 13F IONIS PHARMACEUTICALS COM 462222100 216,140 -26,319 -10.86 10,301 -1.99 0.0116
2024-05-14 2024-03-31 13F IONIS PHARMACEUTICALS COM 462222100 242,459 -3,570 -1.45 10,511 -15.56 0.0120
2024-02-12 2023-12-31 13F IONIS PHARMACEUTICALS COM 462222100 246,029 -174 -0.07 12,447 11.45 0.0157
2023-11-13 2023-09-30 13F IONIS PHARMACEUTICALS COM 462222100 246,203 -22,778 -8.47 11,168 1.19 0.0157
2023-08-14 2023-06-30 13F IONIS PHARMACEUTICALS COM 462222100 268,981 -850 -0.32 11,036 14.45 0.0151
2023-05-12 2023-03-31 13F IONIS PHARMACEUTICALS COM 462222100 269,831 87 0.03 9,644 -5.35 0.0138
2023-02-13 2022-12-31 13F IONIS PHARMACEUTICALS COM 462222100 269,744 -30,269 -10.09 10,188 -23.22 0.0153
2022-11-14 2022-09-30 13F IONIS PHARMACEUTICALS COM 462222100 300,013 -6,307 -2.06 13,269 17.00 0.0217
2022-08-15 2022-06-30 13F IONIS PHARMACEUTICALS COM 462222100 306,320 -34,246 -10.06 11,341 -10.10 0.0177
2022-05-13 2022-03-31 13F IONIS PHARMACEUTICALS COM 462222100 340,566 -17,382 -4.86 12,615 15.82 0.0172
2022-02-14 2021-12-31 13F IONIS PHARMACEUTICALS COM 462222100 357,948 -18,271 -4.86 10,892 -13.69 0.0144
2021-11-15 2021-09-30 13F IONIS PHARMACEUTICALS COM 462222100 376,219 -1,466 -0.39 12,619 -16.24 0.0185
2021-08-13 2021-06-30 13F IONIS PHARMACEUTICALS COM 462222100 377,685 -2,713 -0.71 15,066 -11.91 0.0225
2021-05-14 2021-03-31 13F IONIS PHARMACEUTICALS COM 462222100 380,398 16,156 4.44 17,103 -16.96 0.0282
2021-02-12 2020-12-31 13F IONIS PHARMACEUTICALS COM 462222100 364,242 3,064 0.85 20,595 20.17 0.0367
2020-11-16 2020-09-30 13F IONIS PHARMACEUTICALS COM 462222100 361,178 -13,199 -3.53 17,138 -22.36 0.0353
2020-08-14 2020-06-30 13F IONIS PHARMACEUTICALS COM 462222100 374,377 -16,319 -4.18 22,073 19.39 0.0508
2020-05-14 2020-03-31 13F IONIS PHARMACEUTICALS COM 462222100 390,696 917 0.24 18,488 -21.46 0.0511
2020-02-13 2019-12-31 13F IONIS PHARMACEUTICALS COM 462222100 389,779 -16,960 -4.17 23,539 -3.38 0.0490
2019-11-19 2019-09-30 13F/A-1 IONIS PHARMACEUTICALS COM 462222100 406,739 -17,422 -4.11 24,362 -10.64 0.0622
2019-11-13 2019-09-30 13F IONIS PHARMACEUTICALS COM 462222100 405,743 -18,418 24,302 13,622.4891
2019-08-14 2019-06-30 13F IONIS PHARMACEUTICALS COM 462222100 424,161 -46,738 -9.93 27,262 -28.63 0.0703
2019-05-14 2019-03-31 13F IONIS PHARMACEUTICALS COM 462222100 470,899 -115,001 -19.63 38,196 20.67 0.1079
2019-02-13 2018-12-31 13F IONIS PHARMACEUTICALS COM 462222100 585,900 -20,127 -3.32 31,654 1.25 0.1024
2018-11-13 2018-09-30 13F IONIS PHARMACEUTICALS COM 462222100 606,027 -18,480 -2.96 31,264 19.95 0.0896
2018-08-14 2018-06-30 13F IONIS PHARMACEUTICALS COM 462222100 624,507 15,744 2.59 26,065 -2.81 0.0800
2018-05-11 2018-03-31 13F IONIS PHARMACEUTICALS COM 462222100 608,763 -796 -0.13 26,818 -12.61 0.0846
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS COM 462222100 609,559 -3,393 -0.55 30,687 -1.30 0.0973
2017-11-13 2017-09-30 13F IONIS PHARMACEUTICALS COM 462222100 612,952 13,420 2.24 31,090 1.93 0.1079
2017-08-14 2017-06-30 13F IONIS PHARMACEUTICALS COM 462222100 599,532 1,684 0.28 30,502 27.05 0.1133
2017-05-10 2017-03-31 13F IONIS PHARMACEUTICALS COM 462222100 597,848 3,655 0.62 24,008 -15.57 0.0929
2017-02-16 2016-12-31 13F IONIS PHARMACEUTICALS COM 462222100 594,193 33,497 5.97 28,435 38.27 0.1207
2016-11-15 2016-09-30 13F IONIS PHARMACEUTICALS COM 462222100 560,696 -33,612 -5.66 20,565 48.56 0.0925
2016-08-17 2016-06-30 13F IONIS PHARMACEUTICALS COM 462222100 594,308 594,308 0.00 13,843 0.0640
2016-05-16 2016-03-31 13F IONIS PHARMACEUTICALS COM 462222100 0 -618,066 -100.00 0 -100.00
2016-03-21 2015-12-31 13F/A-2 IONIS PHARMACEUTICALS COM 462222100 618,066 19,592 3.27 38,277 58.23 0.1993
2016-02-26 2015-12-31 13F/A-1 IONIS PHARMACEUTICALS COM 462222100 617,901 -165 38,265 0.2001
2016-02-16 2015-12-31 13F IONIS PHARMACEUTICALS COM 462222100 598,206 38,686
2015-11-16 2015-09-30 13F ISIS PHARMACEUTICALS COM 464330109 598,474 -2,830 -0.47 24,190 -30.00 0.1359
2015-08-17 2015-06-30 13F/A-1 ISIS PHARMACEUTICALS COM 464330109 601,304 2,175 0.36 34,556 -9.41 0.1786
2015-08-17 2015-06-30 13F ISIS PHARMACEUTICALS COM 464330109 594,447 34,210
2015-05-14 2015-03-31 13F ISIS PHARMACEUTICALS COM 464330109 599,129 -265,759 -30.73 38,147 -36.92 0.2088
2015-02-13 2014-12-31 13F ISIS PHARMACEUTICALS COM 464330109 864,888 -197,548 -18.59 60,477 46.60 0.3360
2014-11-13 2014-09-30 13F ISIS PHARMACEUTICALS COM 464330109 1,062,436 10,208 0.97 41,254 13.81 0.3621
2014-08-14 2014-06-30 13F ISIS PHARMACEUTICALS COM 464330109 1,052,228 203,132 23.92 36,249 -1.20 0.3255
2014-05-15 2014-03-31 13F ISIS PHARMACEUTICALS COM 464330109 849,096 849,096 36,689 0.3511
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.