Ionis Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US4622221004

SecurityIONS / Ionis Pharmaceuticals, Inc.
InstitutionNeuberger Berman Group LLC
Latest Disclosed Ownership443,272 shares
Latest Disclosed Value $ 33,285,294
Neuberger Berman Group LLC reports 310.27% increase in ownership of IONS / Ionis Pharmaceuticals, Inc.

On May 14, 2026 - Neuberger Berman Group LLC filed a 13F-HR form disclosing ownership of 443,272 shares of Ionis Pharmaceuticals, Inc. (US:IONS) valued at $33,285,294 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 108,044 shares of Ionis Pharmaceuticals, Inc.. This represents a change in shares of 310.27% during the quarter. The current value of the position is $33,014,899 USD.

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 Common 462222100 443,272 335,228 310.27 33,285 289.43 0.0129
2026-02-13 2025-12-31 13F IONIS PHARMACEUTICALS Common 462222100 108,044 -6,699 -5.84 8,547 13.87 0.0064
2025-11-12 2025-09-30 13F IONIS PHARMACEUTICALS Common 462222100 114,743 120 0.10 7,506 65.77 0.0055
2025-08-25 2025-06-30 13F/A-1 IONIS PHARMACEUTICALS Common 462222100 114,623 12,150 11.86 4,529 46.49 0.0035
2025-08-13 2025-06-30 13F IONIS PHARMACEUTICALS Common 462222100 114,623 12,150 4,529 0.0018
2025-05-13 2025-03-31 13F IONIS PHARMACEUTICALS Common 462222100 102,473 5,842 6.05 3,092 -8.50 0.0026
2025-02-13 2024-12-31 13F IONIS PHARMACEUTICALS Common 462222100 96,631 31,757 48.95 3,378 30.02 0.0027
2024-11-14 2024-09-30 13F IONIS PHARMACEUTICALS Common 462222100 64,874 50,562 353.28 2,599 280.94 0.0020
2024-11-14 2024-06-30 13F/A-1 IONIS PHARMACEUTICALS Common 462222100 14,312 78 0.55 682 10.53 0.0006
2024-08-13 2024-06-30 13F IONIS PHARMACEUTICALS Common 462222100 14,312 78 682 0.0006
2024-11-14 2024-03-31 13F/A-1 IONIS PHARMACEUTICALS Common 462222100 14,234 236 1.69 617 -12.85 0.0005
2024-05-13 2024-03-31 13F IONIS PHARMACEUTICALS Common 462222100 14,234 236 617 0.0005
2024-11-14 2023-12-31 13F/A-2 IONIS PHARMACEUTICALS Common 462222100 13,998 -1,536 -9.89 708 0.57 0.0006
2024-02-09 2023-12-31 13F IONIS PHARMACEUTICALS Common 462222100 13,998 -1,536 708 0.0006
2023-11-14 2023-09-30 13F IONIS PHARMACEUTICALS Common 462222100 15,534 328 2.16 705 13.00 0.0006
2023-08-11 2023-06-30 13F IONIS PHARMACEUTICALS Common 462222100 15,206 74 0.49 624 15.37 0.0006
2023-05-12 2023-03-31 13F IONIS PHARMACEUTICALS Common 462222100 15,132 4,147 37.75 541 30.43 0.0005
2023-02-13 2022-12-31 13F IONIS PHARMACEUTICALS Common 462222100 10,985 -214 -1.91 415 -16.36 0.0004
2022-11-15 2022-09-30 13F IONIS PHARMACEUTICALS Common 462222100 11,199 113 1.02 495 20.73 0.0005
2022-08-15 2022-06-30 13F IONIS PHARMACEUTICALS Common 462222100 11,086 11,086 410 0.0004
2019-05-13 2019-03-31 13F IONIS PHARMACEUTICALS Common 462222100 0 -5,341 -100.00 0 -100.00
2019-02-12 2018-12-31 13F IONIS PHARMACEUTICALS Common 462222100 5,341 0 0.00 289 5.09 0.0004
2018-11-16 2018-09-30 13F/A-1 IONIS PHARMACEUTICALS Common 462222100 5,341 -15,611 -74.51 275 -68.50 0.0003
2018-11-13 2018-09-30 13F IONIS PHARMACEUTICALS Common 462222100 5,341 -15,611 275
2018-08-13 2018-06-30 13F IONIS PHARMACEUTICALS Common 462222100 20,952 14,912 246.89 873 228.20 0.0010
2018-05-08 2018-03-31 13F IONIS PHARMACEUTICALS Common 462222100 6,040 -4,832 -44.44 266 -51.37 0.0003
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS Common 462222100 10,872 -12,900 -54.27 547 -54.61 0.0006
2017-11-15 2017-09-30 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 23,772 -5,640 -19.18 1,205 -19.45 0.0015
2017-08-08 2017-06-30 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 29,412 -1,399 -4.54 1,496 20.74 0.0019
2017-05-10 2017-03-31 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 30,811 -12,396 -28.69 1,239 -40.06 0.0016
2017-02-06 2016-12-31 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 43,207 22,766 111.37 2,067 175.97 0.0028
2016-11-02 2016-09-30 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 20,441 -75 -0.37 749 56.69 0.0010
2016-08-05 2016-06-30 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 20,516 3,948 23.83 478 -28.76 0.0007
2016-05-06 2016-03-31 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 16,568 -201 -1.20 671 -35.42 0.0009
2016-01-28 2015-12-31 13F IONIS PHARMACEUTICALS COMMON STOCK 462222100 16,769 -6,968 -29.36 1,039 8.34 0.0014
2015-11-10 2015-09-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 23,737 -598 -2.46 959 -31.50 0.0012
2015-07-31 2015-06-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 24,335 352 1.47 1,400 -8.32 0.0016
2015-05-06 2015-03-31 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 23,983 23,983 1,527 0.0016
2015-02-05 2014-12-31 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 0 -24,044 -100.00 0 -100.00
2014-11-04 2014-09-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 24,044 -3,044 -11.24 933 0.00 0.0010
2014-08-05 2014-06-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 27,088 -3,636 -11.83 933 -29.74 0.0009
2014-05-05 2014-03-31 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 30,724 1,767 6.10 1,328 15.08 0.0014
2014-02-11 2013-12-31 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 28,957 -2,719 -8.58 1,154 -2.94 0.0012
2013-10-29 2013-09-30 13F/A-1 ISIS PHARMACEUTICALS COMMON STOCK 464330109 31,676 -1,541 -4.64 1,189 33.15 0.0013
2013-10-29 2013-09-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 17,245 151
2013-08-13 2013-06-30 13F ISIS PHARMACEUTICALS COMMON STOCK 464330109 33,217 33,217 893 0.0011
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.