Ionis Pharmaceuticals, Inc.
GB ˙ LSE ˙ US4622221004
75,40 $ ↑1,57 (2,13%)
2026-06-04
DEL PRIS
SecurityGB:0JDI / Ionis Pharmaceuticals, Inc.
InstitutionBlackRock, Inc.
Latest Disclosed Ownership9,066,517 shares
Ownership 5.70%
BlackRock, Inc. ownership in 0JDI / Ionis Pharmaceuticals, Inc.

2025-04-17 - BlackRock, Inc. has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 9,066,517 shares of Ionis Pharmaceuticals, Inc. (GB:0JDI). This represents 5.7 percent ownership of the company. In their previous filing dated 2024-01-26 , BlackRock, Inc. had reported owning 9,057,282 shares, indicating an increase of 0.10 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2025-04-17 2025-04-17 13G/A 9,057,282 9,066,517 0.10 5.70 -9.52
2024-01-26 2024-01-26 13G/A 9,182,911 9,057,282 -1.37 6.30 -3.08
2023-02-01 2023-02-01 13G/A 8,539,282 9,182,911 7.54 6.50 8.33
2022-02-01 2022-02-01 13G 9,750,502 8,539,282 -12.42 6.00 -14.29
2021-02-05 2021-02-05 13G/A 8,402,389 9,750,502 16.04 7.00 16.67
2020-02-10 2020-02-10 13G/A 7,676,257 8,402,389 9.46 6.00 7.14
2019-02-04 2019-02-04 13G/A 6,972,606 7,676,257 10.09 5.60 0.00
2018-01-25 2018-01-25 13G/A 6,457,810 6,972,606 7.97 5.60 5.66
2017-01-30 2017-01-30 13G 6,034,750 6,457,810 7.01 5.30 6.21
2016-09-09 2016-09-09 13G/A 8,182,073 6,034,750 -26.24 4.99 -26.62
2016-02-10 2016-02-10 13G/A 8,182,073 6.80
2015-01-23 2015-01-23 13G/A 9,541,651 8.10
2014-01-29 2014-01-29 13G/A 8,844,551 7.60
2013-02-08 2013-02-08 13G/A 7,565,293 7.48
2012-02-13 2012-02-13 13G/A 5,710,296 5.73

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 IONIS PHARMACEUTICALS COM 462222100 10,442,476 -205,387 -1.93 784,126 -6.91 0.0010
2026-02-12 2025-12-31 13F IONIS PHARMACEUTICALS COM 462222100 10,647,863 199,923 1.91 842,352 23.24 0.0142
2025-11-12 2025-09-30 13F IONIS PHARMACEUTICALS COM 462222100 10,447,940 -448,997 -4.12 683,504 58.76 0.0120
2025-08-12 2025-06-30 13F IONIS PHARMACEUTICALS COM 462222100 10,896,937 -367,505 -3.26 430,538 26.69 0.0082
2025-05-02 2025-03-31 13F IONIS PHARMACEUTICALS COM 462222100 11,264,442 -401,106 -3.44 339,848 -16.67 0.0071
2025-02-07 2024-12-31 13F IONIS PHARMACEUTICALS COM 462222100 11,665,548 852,525 7.88 407,828 -5.85 0.0083
2024-11-13 2024-09-30 13F IONIS PHARMACEUTICALS COM 462222100 10,813,023 491,993 4.77 433,170 -11.94 0.0091
2024-08-13 2024-06-30 13F IONIS PHARMACEUTICALS COM 462222100 10,321,030 549,139 5.62 491,900 16.12 0.0111
2024-05-10 2024-03-31 13F IONIS PHARMACEUTICALS COM 462222100 9,771,891 714,361 7.89 423,611 -7.55 0.0099
2024-02-13 2023-12-31 13F IONIS PHARMACEUTICALS COM 462222100 9,057,530 -57,097 -0.63 458,220 10.83 0.0117
2023-11-13 2023-09-30 13F IONIS PHARMACEUTICALS COM 462222100 9,114,627 -21,547 -0.24 413,439 10.29 0.0119
2023-08-11 2023-06-30 13F IONIS PHARMACEUTICALS COM 462222100 9,136,174 153,928 1.71 374,857 16.77 0.0103
2023-05-12 2023-03-31 13F IONIS PHARMACEUTICALS COM 462222100 8,982,246 -97,311 -1.07 321,025 -6.39 0.0095
2023-02-13 2022-12-31 13F IONIS PHARMACEUTICALS COM 462222100 9,079,557 143,495 1.61 342,935 -13.23 0.0107
2022-11-14 2022-09-30 13F IONIS PHARMACEUTICALS COM 462222100 8,936,062 104,672 1.19 395,240 20.89 0.0134
2022-08-12 2022-06-30 13F IONIS PHARMACEUTICALS COM 462222100 8,831,390 387,547 4.59 326,937 4.53 0.0105
2022-05-12 2022-03-31 13F IONIS PHARMACEUTICALS COM 462222100 8,443,843 -95,439 -1.12 312,761 20.36 0.0084
2022-02-10 2021-12-31 13F IONIS PHARMACEUTICALS COM 462222100 8,539,282 419,429 5.17 259,849 -4.59 0.0066
2021-11-09 2021-09-30 13F IONIS PHARMACEUTICALS COM 462222100 8,119,853 -59,813 -0.73 272,339 -16.53 0.0076
2021-08-11 2021-06-30 13F IONIS PHARMACEUTICALS COM 462222100 8,179,666 -1,628,896 -16.61 326,288 -26.01 0.0091
2021-05-07 2021-03-31 13F IONIS PHARMACEUTICALS COM 462222100 9,808,562 58,060 0.60 440,995 -20.01 0.0130
2021-02-05 2020-12-31 13F IONIS PHARMACEUTICALS COM 462222100 9,750,502 1,285,095 15.18 551,292 37.25 0.0176
2020-11-06 2020-09-30 13F IONIS PHARMACEUTICALS COM 462222100 8,465,407 -185,321 -2.14 401,681 -21.25 0.0148
2020-08-14 2020-06-30 13F IONIS PHARMACEUTICALS COM 462222100 8,650,728 482,788 5.91 510,048 32.08 0.0204
2020-05-01 2020-03-31 13F IONIS PHARMACEUTICALS COM 462222100 8,167,940 -234,449 -2.79 386,180 -23.92 0.0189
2020-02-13 2019-12-31 13F IONIS PHARMACEUTICALS COM 462222100 8,402,389 51,590 0.62 507,588 1.46 0.0195
2019-11-08 2019-09-30 13F IONIS PHARMACEUTICALS COM 462222100 8,350,799 -451,777 -5.13 500,297 -11.57 0.0210
2019-08-22 2019-06-30 13F/A-1 IONIS PHARMACEUTICALS COM 462222100 8,802,576 1,181,004 15.50 565,743 -8.55 0.0242
2019-08-13 2019-06-30 13F IONIS PHARMACEUTICALS COM 462222100 8,802,576 1,181,004 565,743
2019-05-09 2019-03-31 13F IONIS PHARMACEUTICALS COM 462222100 7,621,572 -54,685 -0.71 618,644 49.08 0.0276
2019-02-08 2018-12-31 13F IONIS PHARMACEUTICALS COM 462222100 7,676,257 213,000 2.85 414,977 7.80 0.0209
2018-11-09 2018-09-30 13F IONIS PHARMACEUTICALS COM 462222100 7,463,257 408,678 5.79 384,955 30.95 0.0167
2018-08-09 2018-06-30 13F IONIS PHARMACEUTICALS COM 462222100 7,054,579 124,233 1.79 293,965 -3.77 0.0135
2018-05-09 2018-03-31 13F IONIS PHARMACEUTICALS COM 462222100 6,930,346 -42,260 -0.61 305,489 -12.90 0.0146
2018-02-09 2017-12-31 13F IONIS PHARMACEUTICALS COM 462222100 6,972,606 -30,885 -0.44 350,722 -1.23 0.0167
2017-11-14 2017-09-30 13F IONIS PHARMACEUTICALS COM 462222100 7,003,491 179,504 2.63 355,077 2.29 0.0179
2017-08-10 2017-06-30 13F IONIS PHARMACEUTICALS COM 462222100 6,823,987 264,179 4.03 347,135 31.64 0.0184
2017-05-12 2017-03-31 13F IONIS PHARMACEUTICALS COM 462222100 6,559,808 6,542,394 37,569.74 263,704 31,557.14 0.0145
2017-02-10 2016-12-31 13F IONIS PHARMACEUTICALS COM 462222100 17,414 -1,541 -8.13 833 19.86 0.0012
2016-11-08 2016-09-30 13F IONIS PHARMACEUTICALS COM 462222100 18,955 -82,238 -81.27 695 -70.51 0.0010
2016-08-10 2016-06-30 13F IONIS PHARMACEUTICALS COM 462222100 101,193 -75,463 -42.72 2,357 -67.06 0.0035
2016-05-10 2016-03-31 13F IONIS PHARMACEUTICALS COM 462222100 176,656 -10,553 -5.64 7,155 -38.29 0.0115
2016-02-11 2015-12-31 13F IONIS PHARMACEUTICALS COM 462222100 187,209 63,388 51.19 11,594 131.65 0.0170
2015-11-13 2015-09-30 13F ISIS PHARMACEUTICALS COM 464330109 123,821 -34,154 -21.62 5,005 -44.95 0.0078
2015-08-07 2015-06-30 13F ISIS PHARMACEUTICALS COM 464330109 157,975 -113,103 -41.72 9,091 -47.33 0.0135
2015-05-13 2015-03-31 13F ISIS PHARMACEUTICALS COM 464330109 271,078 114,013 72.59 17,259 77.98 0.0239
2015-02-09 2014-12-31 13F ISIS PHARMACEUTICALS COM 464330109 157,065 153,700 4,567.61 9,697 7,359.23 0.0139
2014-10-29 2014-09-30 13F ISIS PHARMACEUTICALS COM 464330109 3,365 -1,570 -31.81 130 -23.53 0.0002
2014-08-06 2014-06-30 13F ISIS PHARMACEUTICALS COM 464330109 4,935 -78,545 -94.09 170 -95.29 0.0003
2014-05-02 2014-03-31 13F ISIS PHARMACEUTICALS COM 464330109 83,480 -37,444 -30.96 3,607 -25.13 0.0058
2014-02-12 2013-12-31 13F ISIS PHARMACEUTICALS COM 464330109 120,924 117,387 3,318.83 4,818 3,522.56 0.0079
2013-11-12 2013-09-30 13F ISIS PHARMACEUTICALS COM 464330109 3,537 0 0.00 133 40.00 0.0003
2013-08-13 2013-06-30 13F ISIS PHARMACEUTICALS COM 464330109 3,537 3,537 95 0.0002
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.