IONIS PHARMACEUTICALS INC (IONS)
Every FINRA and SEC series the site collects for IONIS PHARMACEUTICALS INC: short interest with days to cover, daily short sale volume, fails to deliver and Form 4 insider trades. Listed on Nasdaq, classified by the SEC as pharmaceutical preparations.
20.9M
Short interest
settlement 2026-08-14
9.6
Days to cover
-2.6% vs prior
42.0%
Short share of volume
2026-09-11
200
Fails to deliver
settlement 2026-08-14
-$2.6M
Insider flow, 90 days
2 buys, 5 sells
As of 2026-09-11.
Short interest
FINRA, twice a month; the last 12 months shown, all 48 settlements in the JSONAs of 14 August 2026, short interest in IONS is 20,909,181 shares, up 866,302 shares over the last month. Over the last 48 readings it ranged from 9,869,851 shares (15 October 2024) to 21,466,123 shares (31 July 2026). The latest reading sits at the top of that range. At the reported average volume of 2.2M shares a day that is 9.6 days to cover, elevated.
Embed this chartfree, with the attribution line it carries
<iframe src="https://xoomar.com/embed/stocks/ions" width="100%" height="440" style="border:0;max-width:100%" loading="lazy" title="XOOMAR chart"></iframe>
| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-08-14 | 20,909,181 | -2.6% | 2,172,496 | 9.62 |
| 2026-07-31 | 21,466,123 | +7.1% | 3,382,861 | 6.35 |
| 2026-07-15 | 20,042,879 | +15.0% | 5,450,805 | 3.68 |
| 2026-06-30 | 17,425,020 | -1.9% | 2,377,735 | 7.33 |
| 2026-06-15 | 17,757,362 | +4.5% | 1,668,579 | 10.64 |
| 2026-05-29 | 16,986,466 | +5.6% | 1,702,170 | 9.98 |
| 2026-05-15 | 16,086,234 | -1.2% | 1,608,774 | 10.00 |
| 2026-04-30 | 16,279,706 | +18.3% | 2,023,751 | 8.04 |
| 2026-04-15 | 13,762,159 | -4.0% | 1,443,237 | 9.54 |
| 2026-03-31 | 14,330,826 | +2.7% | 2,418,365 | 5.93 |
| 2026-03-13 | 13,949,702 | -9.0% | 2,453,957 | 5.68 |
| 2026-02-27 | 15,323,236 | -1.1% | 2,217,431 | 6.91 |
| 2026-02-13 | 15,487,922 | -0.3% | 1,851,249 | 8.37 |
| 2026-01-30 | 15,537,729 | +13.2% | 2,668,640 | 5.82 |
| 2026-01-15 | 13,729,783 | -7.8% | 2,082,127 | 6.59 |
| 2025-12-31 | 14,885,370 | -7.5% | 1,568,746 | 9.49 |
| 2025-12-15 | 16,086,183 | +2.9% | 2,020,355 | 7.96 |
| 2025-11-28 | 15,626,208 | +9.9% | 2,624,122 | 5.95 |
| 2025-11-14 | 14,223,973 | +12.3% | 3,736,097 | 3.81 |
| 2025-10-31 | 12,661,274 | -7.6% | 1,914,799 | 6.61 |
| 2025-10-15 | 13,699,358 | +11.6% | 2,279,250 | 6.01 |
| 2025-09-30 | 12,278,792 | +2.6% | 1,991,945 | 6.16 |
| 2025-09-15 | 11,972,594 | +14.0% | 4,802,271 | 2.49 |
| 2025-08-29 | 10,502,338 | -2.6% | 1,766,631 | 5.94 |
Daily short volume
FINRA Reg SHO, last 60 sessions. JSONAs of 11 September 2026, the short share of IONS volume is 42.0%, up 14.7 points over the last five sessions. Over the last 52 readings it ranged from 20.2% (9 September 2026) to 77.6% (2 July 2026). The latest reading is 7.3 points below the 30-session average of 49.3%, on 846K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-09-11 | 355K | 846K | 42.0% | 5,954 |
| 2026-09-10 | 308K | 1.0M | 30.6% | 267 |
| 2026-09-09 | 248K | 1.2M | 20.2% | 2,257 |
| 2026-09-08 | 1.3M | 4.4M | 29.6% | 32,618 |
| 2026-09-04 | 351K | 914K | 38.4% | 30,784 |
| 2026-09-03 | 553K | 2.0M | 27.3% | 17,226 |
| 2026-09-02 | 340K | 741K | 45.9% | 124 |
| 2026-09-01 | 306K | 633K | 48.3% | 778 |
| 2026-08-31 | 380K | 649K | 58.5% | 2,602 |
| 2026-08-28 | 444K | 715K | 62.1% | 57,284 |
| 2026-08-27 | 384K | 574K | 66.8% | 976 |
| 2026-08-26 | 756K | 1.0M | 75.2% | 1,158 |
| 2026-08-25 | 624K | 1.0M | 61.4% | 12,662 |
| 2026-08-24 | 521K | 864K | 60.4% | 14,210 |
| 2026-08-21 | 589K | 1.3M | 46.3% | 430 |
| 2026-08-20 | 352K | 862K | 40.9% | 449 |
| 2026-08-19 | 640K | 1.3M | 49.0% | 5,448 |
| 2026-08-18 | 552K | 1.0M | 53.9% | 3,729 |
| 2026-08-17 | 357K | 656K | 54.4% | 3,836 |
| 2026-08-14 | 198K | 590K | 33.5% | 6,000 |
| 2026-08-13 | 268K | 445K | 60.2% | 2,103 |
| 2026-08-12 | 368K | 998K | 36.9% | 1,177 |
| 2026-08-11 | 375K | 1.2M | 32.0% | 3,147 |
| 2026-08-10 | 408K | 716K | 57.0% | 804 |
| 2026-08-07 | 406K | 663K | 61.3% | 2,138 |
| 2026-08-06 | 527K | 1.0M | 52.2% | 2,879 |
| 2026-08-05 | 414K | 889K | 46.6% | 9,723 |
| 2026-08-04 | 660K | 1.1M | 62.3% | 53,387 |
| 2026-08-03 | 673K | 1.0M | 64.1% | 1,586 |
| 2026-07-31 | 611K | 1.0M | 60.4% | 76,653 |
Fails to deliver
SEC, by settlement date. JSONAs of 14 August 2026, the fails-to-deliver balance in IONS is 200 shares, up 25 shares over the last settlement date. Over the last 52 readings it ranged from 1 share (26 March 2026) to 71,539 shares (4 March 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-08-14 | 200 | $55.87 | $11K |
| 2026-08-10 | 175 | $56.56 | $10K |
| 2026-08-06 | 1,952 | $54.19 | $106K |
| 2026-08-04 | 373 | $54.49 | $20K |
| 2026-08-03 | 157 | $51.77 | $8K |
| 2026-07-30 | 4,288 | $54.04 | $232K |
| 2026-07-28 | 156 | $55.96 | $9K |
| 2026-07-23 | 2 | $54.01 | $108 |
| 2026-07-20 | 3,118 | $54.39 | $170K |
| 2026-07-17 | 36 | $54.65 | $2K |
| 2026-07-16 | 3,002 | $54.73 | $164K |
| 2026-07-15 | 51 | $54.93 | $3K |
| 2026-07-14 | 44 | $56.75 | $2K |
| 2026-07-07 | 3,546 | $83.18 | $295K |
| 2026-07-06 | 1,248 | $81.80 | $102K |
| 2026-07-01 | 30,806 | $79.29 | $2.4M |
| 2026-06-30 | 42,698 | $80.69 | $3.4M |
| 2026-06-29 | 11,381 | $81.18 | $924K |
| 2026-06-25 | 1,864 | $76.52 | $143K |
| 2026-06-24 | 3 | $75.99 | $228 |
| 2026-06-23 | 7 | $75.89 | $531 |
| 2026-06-18 | 1,691 | $74.31 | $126K |
| 2026-06-17 | 25 | $73.09 | $2K |
| 2026-06-15 | 1,192 | $73.28 | $87K |
| 2026-06-12 | 7 | $73.82 | $517 |
| 2026-06-09 | 668 | $73.54 | $49K |
| 2026-06-08 | 15 | $74.48 | $1K |
| 2026-06-05 | 40,216 | $75.13 | $3.0M |
| 2026-06-04 | 333 | $73.82 | $25K |
| 2026-06-03 | 2,084 | $72.97 | $152K |
Insider trades
SEC Form 4, newest first, 50 of 100 shown. JSONOver the last 90 days IONS insiders reported 2 open-market buys ($1.1M) against 5 sells ($3.6M), so the dollar flow leans toward selling. Latest filing: O'NEIL PATRICK R. (EVP CLO & General Counsel) on 2026-08-31.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-08-31 | O'NEIL PATRICK R. | EVP CLO & General Counsel | J | 63 | $51.31 | $3K | 59K |
| 2026-08-31 | Monia Brett P | Chief Executive Officer | J | 98 | $51.31 | $5K | 243K |
| 2026-08-31 | Birchler Brian | EVP, Corp and Development Ops | J | 58 | $51.31 | $3K | 103K |
| 2026-08-31 | BENNETT C FRANK | EVP, Chief Scientific Officer | J | 110 | $51.31 | $6K | 60K |
| 2026-07-31 | Hayden Michael R | n/a | Buy | 5K | $51.60 | $258K | 24K |
| 2026-07-30 | Hayden Michael R | n/a | Buy | 15K | $53.38 | $801K | 19K |
| 2026-07-15 | BERTHELSEN SPENCER R | n/a | Option exercise | 5K | $0.00 | $0 | 161K |
| 2026-07-07 | Diaz Allene M. | n/a | Sell | 10K | $85.42 | $864K | 4K |
| 2026-07-07 | Diaz Allene M. | n/a | Option exercise | 10K | $47.11 | $476K | 14K |
| 2026-07-07 | BENNETT C FRANK | EVP, Chief Scientific Officer | Sell | 15K | $85.46 | $1.3M | 0 |
| 2026-07-07 | BENNETT C FRANK | EVP, Chief Scientific Officer | J | 15K | $0.00 | $0 | 15K |
| 2026-07-07 | BENNETT C FRANK | EVP, Chief Scientific Officer | Sell | 6K | $83.58 | $463K | 75K |
| 2026-06-26 | Baroldi Joseph | EVP, Chief Business Officer | Sell | 6K | $80.16 | $452K | 5K |
| 2026-06-26 | Baroldi Joseph | EVP, Chief Business Officer | Option exercise | 2K | $32.60 | $58K | 10K |
| 2026-06-26 | Baroldi Joseph | EVP, Chief Business Officer | Option exercise | 4K | $56.78 | $220K | 9K |
| 2026-06-15 | BERTHELSEN SPENCER R | n/a | Sell | 8K | $73.49 | $588K | 156K |
| 2026-06-15 | BERTHELSEN SPENCER R | n/a | Option exercise | 8K | $24.42 | $195K | 164K |
| 2026-06-01 | BERTHELSEN SPENCER R | n/a | Sell | 8K | $75.67 | $605K | 156K |
| 2026-06-01 | BERTHELSEN SPENCER R | n/a | Option exercise | 8K | $24.42 | $195K | 164K |
| 2026-05-14 | Monia Brett P | Chief Executive Officer | Sell | 3K | $78.68 | $253K | 243K |
| 2026-05-14 | Monia Brett P | Chief Executive Officer | Option exercise | 3K | $32.60 | $105K | 246K |
| 2026-05-13 | Monia Brett P | Chief Executive Officer | Sell | 1K | $78.01 | $103K | 243K |
| 2026-05-13 | Monia Brett P | Chief Executive Officer | Option exercise | 1K | $32.60 | $43K | 244K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Sell | 18K | $75.58 | $1.3M | 36K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Sell | 60K | $74.90 | $4.5M | 54K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Option exercise | 16K | $42.88 | $686K | 86K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Option exercise | 10K | $41.08 | $424K | 70K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Option exercise | 12K | $40.05 | $481K | 59K |
| 2026-05-04 | LOSCALZO JOSEPH | n/a | Option exercise | 11K | $38.06 | $417K | 47K |
| 2026-05-01 | KLEIN JOSEPH III | n/a | Sell | 1K | $74.45 | $107K | 11K |
| 2026-05-01 | KLEIN JOSEPH III | n/a | Sell | 9K | $73.35 | $637K | 12K |
| 2026-05-01 | KLEIN JOSEPH III | n/a | Option exercise | 10K | $47.11 | $476K | 21K |
| 2026-04-28 | Baroldi Joseph | EVP, Chief Business Officer | Sell | 2K | $71.79 | $117K | 45K |
| 2026-04-16 | Jenne Kyle | EVP, Chf GL Pdt Str Ofcr | Sell | 5K | $75.17 | $368K | 24K |
| 2026-04-16 | Birchler Brian | EVP, Corp and Development Ops | Sell | 973 | $75.04 | $73K | 68K |
| 2026-04-16 | Baroldi Joseph | EVP, Chief Business Officer | Sell | 6K | $74.56 | $419K | 47K |
| 2026-04-15 | PARSHALL B LYNNE | n/a | Sell | 534 | $76.97 | $41K | 51K |
| 2026-04-15 | PARSHALL B LYNNE | n/a | Sell | 4K | $76.19 | $340K | 52K |
| 2026-04-15 | Jenne Kyle | EVP, Chf GL Pdt Str Ofcr | Option exercise | 12K | $0.00 | $0 | 29K |
| 2026-04-15 | Birchler Brian | EVP, Corp and Development Ops | Option exercise | 2K | $0.00 | $0 | 68K |
| 2026-04-15 | Baroldi Joseph | EVP, Chief Business Officer | Option exercise | 11K | $0.00 | $0 | 52K |
| 2026-04-02 | Devers Shannon L. | EVP, Chief Human Resources Ofc | Sell | 6K | $74.05 | $459K | 16K |
| 2026-04-01 | KLEIN JOSEPH III | n/a | Sell | 2K | $75.95 | $168K | 11K |
| 2026-04-01 | KLEIN JOSEPH III | n/a | Sell | 20K | $75.50 | $1.5M | 13K |
| 2026-04-01 | KLEIN JOSEPH III | n/a | Option exercise | 10K | $41.08 | $424K | 33K |
| 2026-04-01 | KLEIN JOSEPH III | n/a | Option exercise | 12K | $38.06 | $457K | 23K |
| 2026-03-19 | Schneider Eugene | EVP, Chf Clinical Develop Ofcr | Sell | 6K | $70.97 | $412K | 64K |
| 2026-03-17 | HOUGEN ELIZABETH L | EVP, Finance & CFO | Sell | 10K | $73.21 | $745K | 83K |
| 2026-03-16 | HOUGEN ELIZABETH L | EVP, Finance & CFO | Sell | 9K | $72.77 | $687K | 93K |
| 2026-03-16 | HOUGEN ELIZABETH L | EVP, Finance & CFO | Sell | 206K | $72.38 | $14.9M | 102K |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are the rarer, stronger signal.
13F holders
Tracked managers holding IONS at their latest 13F. JSON10 of the 30 tracked managers held IONS at their latest 13F, $855.6M in total at quarter-end prices. Two Sigma Investments is the largest at $495.7M (0.4% of its portfolio) as of 2026-06-30. Over the prior quarter 4 added shares and 6 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| Two Sigma Investments | 2026-06-30 | 6.3M | $495.7M | 0.36% | +395K |
| Citadel Advisors | 2026-06-30 | 86.5M | $134.7M | 0.02% | +28.5M |
| Citadel Advisors | 2026-06-30 | 855K | $67.8M | 0.01% | -85.6M |
| Renaissance Technologies | 2026-06-30 | 559K | $44.4M | 0.06% | +254K |
| Millennium Management | 2026-06-30 | 546K | $43.3M | 0.02% | -228K |
| D. E. Shaw & Co. | 2026-06-30 | 385K | $30.5M | 0.01% | -45K |
| ARK Investment Management | 2026-06-30 | 301K | $23.8M | 0.15% | +12K |
| Fisher Asset Management | 2026-06-30 | 137K | $10.9M | 0.00% | -4K |
| Point72 Asset Management | 2026-06-30 | 34K | $2.7M | 0.00% | -3K |
| AQR Capital Management | 2026-06-30 | 22K | $1.7M | 0.00% | -7K |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
Financials
SEC XBRL, as filed. JSONIn Q2 2026 (quarter ended 2026-06-30) IONIS PHARMACEUTICALS INC reported revenue of $267.9M, down 40.7% from the same quarter a year earlier, and net loss of $114.6M (-0.69 diluted EPS). In FY 2025 it generated -$268.6M of operating cash flow.
- Cash
- $350.1M
- Equity
- $439.7M
- Total assets
- $2.99B
- Shares outstanding
- 166,184,322
Quarterly, last 8 quarters
| Quarter | Period end | Revenue | Net income | Margin | Diluted EPS |
|---|---|---|---|---|---|
| Q2 2026 | 2026-06-30 | $267.9M | -$114.6M | -42.8% | -0.69 |
| Q1 2026 | 2026-03-31 | $246.1M | -$92.5M | -37.6% | -0.56 |
| Q4 2025 | 2025-12-31 | $203.3M | -$229.4M | -112.8% | -1.41 |
| Q3 2025 | 2025-09-30 | $156.7M | -$128.6M | -82.1% | -0.80 |
| Q2 2025 | 2025-06-30 | $452.0M | $123.6M | 27.3% | 0.70 |
| Q1 2025 | 2025-03-31 | $131.6M | -$146.9M | -111.6% | -0.93 |
| Q4 2024 | 2024-12-31 | $226.6M | -$104.3M | -46.1% | -0.66 |
| Q3 2024 | 2024-09-30 | $133.8M | -$140.5M | -105.0% | -0.95 |
Fiscal years, with buybacks and dividends
| Fiscal year | Ends | Revenue | Net income | Operating cash flow | Capex | Buybacks | Dividends |
|---|---|---|---|---|---|---|---|
| FY 2025 | 2025-12-31 | $943.7M | n/a | -$268.6M | $51.4M | n/a | n/a |
| FY 2024 | 2024-12-31 | $705.1M | n/a | -$500.9M | $45.3M | n/a | n/a |
| FY 2023 | 2023-12-31 | $787.6M | n/a | -$307.5M | $23.8M | n/a | n/a |
| FY 2022 | 2022-12-31 | $587.4M | n/a | -$274.4M | $15.7M | $0 | n/a |
| FY 2021 | 2021-12-31 | $810.5M | n/a | $30.8M | $12.0M | $0 | n/a |
Quarters are the three-month figures the company reports; a fourth quarter marked derived is the fiscal year less the three reported quarters, since companies report it only inside the 10-K. Fiscal years are the annual figures. Buybacks are cash paid to repurchase common stock in the year (XBRL PaymentsForRepurchaseOfCommonStock), not authorizations. Balance sheet lines are as of 2026-06-30; shares outstanding as of 2026-07-23 from the cover page.
What this page is
IONIS PHARMACEUTICALS INC in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page pulls every series the site collects for one ticker onto one URL, keyed by the SEC's own ticker list, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a summary sentence built from the rows (last value, change, range with dates) and its own JSON and CSV links. Nothing on the page is written by a model; the sentences change only when the data does. A page exists only for companies with data in at least two series, and every section says when its source last updated.
This page follows IONIS PHARMACEUTICALS INC (IONS), SEC CIK 874015, listed on Nasdaq, classified by the SEC as pharmaceutical preparations. The cross-market tables live on the short interest and insider transactions hubs.
Source and method
- Short interest
- FINRA consolidated short interestTwice a month, about eight business days after settlement. Latest 2026-08-14.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesEvery trading day, loaded the following morning. Latest 2026-09-11.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataTwice a month, a few weeks after the half month ends. Latest 2026-08-14.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRQuarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Financials
- SEC XBRL company factsRefreshed weekly from the SEC's structured data; values are as filed in the 10-Q and 10-K. Latest 2026-06-30.JSON and CSV
- Insider trades
- SEC EDGAR Form 4EDGAR read every 30 minutes; filings are due two business days after the trade. Latest 2026-08-31.JSON and CSV
- Company record
- EDGAR filing index for CIK 874015Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 30 requests a minute without a key, 120 a minute with a key from a free account.
Data checks. Every dataset is checked against its source once a day. This dataset passed the last run, 13 Sep 05:40 UTC.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a crowded short are the combination that has historically preceded squeezes; insider sells next to a crowded short are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
Other companies the SEC classifies as pharmaceutical preparations
- UTHRUNITED THERAPEUTICS Corp
- CPIXCUMBERLAND PHARMACEUTICALS INC
- LLYELI LILLY & Co
- ALNYALNYLAM PHARMACEUTICALS, INC.
- PTCTPTC THERAPEUTICS, INC.
- MDGLMADRIGAL PHARMACEUTICALS, INC.
- ONCBeOne Medicines Ltd.
- INSMINSMED Inc
- CORTCORCEPT THERAPEUTICS INC
- ROIVRoivant Sciences Ltd.
- BBIOBridgeBio Pharma, Inc.
- CYTKCYTOKINETICS INC
- LGNDLIGAND PHARMACEUTICALS INC
- VRTXVERTEX PHARMACEUTICALS INC / MA
- LQDALiquidia Corp
- SIONSionna Therapeutics, Inc.
- JAZZJazz Pharmaceuticals plc
- BLTEBELITE BIO, INC
- TVTXTravere Therapeutics, Inc.
- PAHCPHIBRO ANIMAL HEALTH CORP
- ARQTArcutis Biotherapeutics, Inc.
- NATRNATURES SUNSHINE PRODUCTS INC
- HOWLWerewolf Therapeutics, Inc.
- JNJJOHNSON & JOHNSON
Datasets
Frequently Asked Questions
How much of IONS is sold short?
What is IONS's daily short volume?
Does IONS have fails to deliver?
Are IONS insiders buying or selling?
What did IONS report last quarter?
Which funds hold IONS?
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.