Ionis Pharmaceuticals, Inc.
GB ˙ LSE ˙ US4622221004
73,83 $ ↑0,93 (1,28%)
2026-06-03
DEL PRIS
SecurityGB:0JDI / Ionis Pharmaceuticals, Inc.
InstitutionCss Llc/il
Latest Disclosed Ownership79,093 shares
Latest Disclosed Value $ 5,939,093
Css Llc/il ownership in 0JDI / Ionis Pharmaceuticals, Inc.

On May 15, 2026 - Css Llc/il filed a 13F-HR form disclosing ownership of 79,093 shares of Ionis Pharmaceuticals, Inc. (GB:0JDI) valued at $5,947,635 USD as of March 31, 2026. The entity filed a previous 13F-HR on August 16, 2021 disclosing 0 shares of Ionis Pharmaceuticals, Inc.. The current value of the position is $5,839,436 USD.

Css Llc/il has a history of taking positions in derivatives of the underlying security (0JDI) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 2,000 of underlying shares valued at $150,180 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

GB:0JDI / Ionis Pharmaceuticals, Inc. Historical Put/Call Ratio
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)
2026-05-15 2026-03-31 13F IONIS PHARMACEUTICALS COM 462222100 79,093 79,093 5,939 0.2845
2021-08-16 2021-06-30 13F IONIS PHARMACEUTICALS COM 462222100 0 -9,605 -100.00 0 -100.00
2021-05-17 2021-03-31 13F IONIS PHARMACEUTICALS COM 462222100 9,605 9,605 432 0.0178
2020-05-15 2020-03-31 13F IONIS PHARMACEUTICALS COM 462222100 0 -98,235 -100.00 0 -100.00
2020-02-14 2019-12-31 13F IONIS PHARMACEUTICALS COM 462222100 98,235 89,646 1,043.73 5,934 1,052.23 0.3286
2019-11-14 2019-09-30 13F IONIS PHARMACEUTICALS COM 462222100 8,589 6,066 240.43 515 217.90 0.0331
2019-08-14 2019-06-30 13F IONIS PHARMACEUTICALS COM 462222100 2,523 2,523 162 0.0093
2019-02-14 2018-12-31 13F IONIS PHARMACEUTICALS COM 462222100 0 -7,136 -100.00 0 -100.00
2018-11-14 2018-09-30 13F IONIS PHARMACEUTICALS COM 462222100 7,136 3,236 82.97 368 125.77 0.0157
2018-08-14 2018-06-30 13F IONIS PHARMACEUTICALS COM 462222100 3,900 3,900 163 0.0076
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS COM 462222100 0 -11,937 -100.00 0 -100.00
2017-11-14 2017-09-30 13F IONIS PHARMACEUTICALS COM 462222100 11,937 11,937 605 0.0296
2017-08-14 2017-06-30 13F IONIS PHARMACEUTICALS COM 462222100 0 -10,232 -100.00 0 -100.00
2017-05-15 2017-03-31 13F IONIS PHARMACEUTICALS COM 462222100 10,232 10,232 411 0.0246
2015-08-14 2015-06-30 13F ISIS PHARMACEUTICALS COM 464330109 0 -17,824 -100.00 0 -100.00
2015-05-15 2015-03-31 13F ISIS PHARMACEUTICALS COM 464330109 17,824 17,824 1,135 0.0577
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-17 2025-12-31 13F IONIS PHARMACEUTICALS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-13 2025-09-30 13F IONIS PHARMACEUTICALS COM Call 4,000 262 n/a n/a n/a
2020-05-15 2020-03-31 13F IONIS PHARMACEUTICALS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-14 2019-12-31 13F IONIS PHARMACEUTICALS COM Call 15,000 0.00 906 0.78 n/a n/a n/a
2019-11-14 2019-09-30 13F IONIS PHARMACEUTICALS COM Call 15,000 150.00 899 132.90 n/a n/a n/a
2019-08-14 2019-06-30 13F IONIS PHARMACEUTICALS COM Call 6,000 -16.67 386 -34.02 n/a n/a n/a
2019-05-15 2019-03-31 13F IONIS PHARMACEUTICALS COM Call 7,200 -22.58 585 16.30 n/a n/a n/a
2019-02-14 2018-12-31 13F IONIS PHARMACEUTICALS COM Call 9,300 14.81 503 20.33 n/a n/a n/a
2018-11-14 2018-09-30 13F IONIS PHARMACEUTICALS COM Call 8,100 418 n/a n/a n/a
2018-08-14 2018-06-30 13F IONIS PHARMACEUTICALS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-05-15 2018-03-31 13F IONIS PHARMACEUTICALS COM Call 8,000 -63.64 352 -68.20 n/a n/a n/a
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS COM Call 22,000 83.33 1,107 82.07 n/a n/a n/a
2017-11-14 2017-09-30 13F IONIS PHARMACEUTICALS COM Call 12,000 608 n/a n/a n/a
2016-05-16 2016-03-31 13F IONIS PHARMACEUTICALS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-02-16 2015-12-31 13F IONIS PHARMACEUTICALS COM Call 5,000 310 n/a n/a n/a
2014-11-14 2014-09-30 13F ISIS PHARMACEUTICALS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2014-08-14 2014-06-30 13F ISIS PHARMACEUTICALS COM Call 10,000 344 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F IONIS PHARMACEUTICALS COM Put 2,000 150 n/a n/a n/a
2025-05-15 2025-03-31 13F IONIS PHARMACEUTICALS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-18 2024-12-31 13F IONIS PHARMACEUTICALS COM Put 15,100 0.00 528 -12.75 n/a n/a n/a
2024-11-14 2024-09-30 13F IONIS PHARMACEUTICALS COM Put 15,100 0.00 605 -15.99 n/a n/a n/a
2024-08-14 2024-06-30 13F IONIS PHARMACEUTICALS COM Put 15,100 202.00 720 232.87 n/a n/a n/a
2024-05-15 2024-03-31 13F IONIS PHARMACEUTICALS COM Put 5,000 217 n/a n/a n/a
2020-08-14 2020-06-30 13F IONIS PHARMACEUTICALS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-15 2020-03-31 13F IONIS PHARMACEUTICALS COM Put 5,100 -95.99 241 -96.86 n/a n/a n/a
2020-02-14 2019-12-31 13F IONIS PHARMACEUTICALS COM Put 127,100 638.95 7,677 644.62 n/a n/a n/a
2019-11-14 2019-09-30 13F IONIS PHARMACEUTICALS COM Put 17,200 290.91 1,031 264.31 n/a n/a n/a
2019-08-14 2019-06-30 13F IONIS PHARMACEUTICALS COM Put 4,400 0.00 283 -20.73 n/a n/a n/a
2019-05-15 2019-03-31 13F IONIS PHARMACEUTICALS COM Put 4,400 -85.53 357 -78.28 n/a n/a n/a
2019-02-14 2018-12-31 13F IONIS PHARMACEUTICALS COM Put 30,400 0.00 1,644 4.85 n/a n/a n/a
2018-11-14 2018-09-30 13F IONIS PHARMACEUTICALS COM Put 30,400 111.11 1,568 160.90 n/a n/a n/a
2018-08-14 2018-06-30 13F IONIS PHARMACEUTICALS COM Put 14,400 -31.43 601 -35.10 n/a n/a n/a
2018-05-15 2018-03-31 13F IONIS PHARMACEUTICALS COM Put 21,000 162.50 926 129.78 n/a n/a n/a
2018-02-14 2017-12-31 13F IONIS PHARMACEUTICALS COM Put 8,000 0.00 403 -0.74 n/a n/a n/a
2017-11-14 2017-09-30 13F IONIS PHARMACEUTICALS COM Put 8,000 406 n/a n/a n/a
2017-05-15 2017-03-31 13F IONIS PHARMACEUTICALS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-02-14 2016-12-31 13F IONIS PHARMACEUTICALS COM Put 8,100 0.00 387 30.74 n/a n/a n/a
2016-11-14 2016-09-30 13F IONIS PHARMACEUTICALS COM Put 8,100 -10.99 296 39.62 n/a n/a n/a
2016-08-15 2016-06-30 13F IONIS PHARMACEUTICALS COM Put 9,100 12.35 212 -35.17 n/a n/a n/a
2016-05-16 2016-03-31 13F IONIS PHARMACEUTICALS COM Put 8,100 -67.07 327 -78.54 n/a n/a n/a
2016-02-16 2015-12-31 13F IONIS PHARMACEUTICALS COM Put 24,600 37.43 1,524 110.50 n/a n/a n/a
2015-11-16 2015-09-30 13F ISIS PHARMACEUTICALS COM Put 17,900 103.41 724 42.80 n/a n/a n/a
2015-08-14 2015-06-30 13F ISIS PHARMACEUTICALS COM Put 8,800 0.00 507 -9.46 n/a n/a n/a
2015-05-15 2015-03-31 13F ISIS PHARMACEUTICALS COM Put 8,800 -82.71 560 -82.18 n/a n/a n/a
2015-02-17 2014-12-31 13F ISIS PHARMACEUTICALS COM Put 50,900 0.00 3,142 59.01 n/a n/a n/a
2014-11-14 2014-09-30 13F ISIS PHARMACEUTICALS COM Put 50,900 0.00 1,976 12.72 n/a n/a n/a
2014-08-14 2014-06-30 13F ISIS PHARMACEUTICALS COM Put 50,900 41.78 1,753 13.02 n/a n/a n/a
2014-05-15 2014-03-31 13F ISIS PHARMACEUTICALS COM Put 35,900 1,551 n/a n/a n/a
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.