Ionis Pharmaceuticals (IONS) Short Interest Ratio & Short Volume $33.50 -0.97 (-2.81%) As of 03:17 PM Eastern This is a fair market value price provided by Polygon.io. Learn more. Add Compare Share Share Short Interest Stock AnalysisAnalyst ForecastsChartCompetitorsEarningsFinancialsHeadlinesInsider TradesOptions ChainOwnershipSEC FilingsShort InterestSustainabilityTrendsBuy This Stock Ionis Pharmaceuticals Short Interest DataIonis Pharmaceuticals (IONS) has a short interest of 14.63 million shares, representing 9.45% of the float (the number of shares available for trading by the public). This marks a 0.55% increase in short interest from the previous month. The short interest ratio (days to cover) is 8.4, indicating that it would take 8.4 days of the average trading volume of 1.55 million shares to cover all short positions.Current Short Interest14,630,000 sharesPrevious Short Interest14,550,000 sharesChange Vs. Previous Month+0.55%Dollar Volume Sold Short$449.29 millionShort Interest Ratio8.4 Days to CoverLast Record DateApril 30, 2025Outstanding Shares159,159,000 sharesFloat Size154,750,000 sharesShort Percent of Float9.45%Today's Trading Volume429,481 sharesAverage Trading Volume1,549,165 sharesToday's Volume Vs. Average28% Short Selling Ionis Pharmaceuticals? Sign up to receive the latest short interest report for Ionis Pharmaceuticals and its competitors with MarketBeat's FREE newsletter. Email Address Skip Charts & View Short Interest HistoryShort Interest ChartDays to Cover ChartShort Percent of Float ChartIONS Short Interest Over TimeIONS Days to Cover Over TimeIONS Percentage of Float Shorted Over Time Ionis Pharmaceuticals Short Interest History Export to ExcelReport DateTotal Shares Sold ShortDollar Volume Sold ShortChange from Previous ReportPercentage of Float ShortedDays to CoverPrice on Report Date 4/30/202514,630,000 shares $449.29 million +0.6%9.5%8.4 $30.71 4/15/202514,550,000 shares $412.93 million +9.1%9.4%8.3 $28.38 3/31/202513,340,000 shares $402.47 million +4.1%8.6%7.7 $30.17 3/15/202512,810,000 shares $422.22 million -0.3%8.3%7.8 $32.96 2/28/202512,850,000 shares $426.49 million +1.4%8.3%7.8 $33.19 2/15/202512,670,000 shares $393.28 million +4.5%8.2%7.7 $31.04 1/31/202512,120,000 shares $386.63 million +18.4%7.9%7.9 $31.90 1/15/202510,240,000 shares $340.07 million -6.1%7.0%7.1 $33.21 12/31/202410,900,000 shares $381.06 million +3.5%7.5%7.8 $34.96 12/15/202410,530,000 shares $385.50 million +0.8%7.2%7.1 $36.61 Get the Latest News and Ratings for IONS and Related StocksEnter your email address below to receive the latest news and analysts' ratings for Ionis Pharmaceuticals and its competitors with MarketBeat's FREE daily newsletter. 11/30/202410,450,000 shares $373.38 million -5.4%7.2%6.1 $35.73 11/15/202411,050,000 shares $379.46 million +2.9%7.6%6.5 $34.34 10/31/202410,740,000 shares $412.31 million +8.8%7.4%7 $38.39 10/15/20249,870,000 shares $373.48 million -6.3%6.8%6.3 $37.84 9/30/202410,530,000 shares $421.83 million -0.8%7.2%6.6 $40.06 9/15/202410,610,000 shares $447.64 million +4.4%7.3%6.4 $42.19 8/31/202410,160,000 shares $484.43 million +2.6%7.6%6.8 $47.68 8/15/20249,900,000 shares $461.98 million +4.7%7.4%8 $46.67 7/31/20249,460,000 shares $467.89 million +1.0%7.0%7 $49.46 7/15/20249,370,000 shares $445.73 million -1.6%7.0%7.2 $47.57 6/30/20249,520,000 shares $453.72 million +10.1%7.1%7.8 $47.66 6/15/20248,650,000 shares $351.62 million +0.6%6.5%7.5 $40.65 5/31/20248,600,000 shares $323.10 million -0.4%6.4%8.3 $37.57 5/15/20248,630,000 shares $338.38 million -1.4%6.4%7.9 $39.21 4/30/20248,750,000 shares $361.03 million -8.2%6.5%8.1 $41.26 4/15/20249,530,000 shares $395.97 million +0.1%7.1%8.9 $41.55 3/31/20249,520,000 shares $412.69 million -1.6%7.1%8.2 $43.35 3/15/20249,670,000 shares $411.46 million +6.2%7.2%8.1 $42.55 2/29/20249,110,000 shares $411.86 million +0.6%6.8%7.4 $45.21 2/15/20249,060,000 shares $410.24 million +7.2%6.8%7.4 $45.28 1/31/20248,450,000 shares $434.25 million -1.1%6.0%7.5 $51.39 1/15/20248,540,000 shares $457.23 million +3.6%6.1%7.4 $53.54 12/31/20238,240,000 shares $416.86 million -3.7%5.9%7.5 $50.59 12/15/20238,560,000 shares $425.43 million -11.8%6.1%7.3 $49.70 11/30/20239,700,000 shares $479.86 million -0.4%6.9%8.7 $49.47 11/15/20239,740,000 shares $484.76 million +0.4%7.0%9.4 $49.77 10/31/20239,700,000 shares $429.42 million +6.2%6.9%9.6 $44.27 10/15/20239,130,000 shares $438.06 million -1.8%6.5%9 $47.98 9/30/20239,300,000 shares $421.85 million -0.9%6.6%9.2 $45.36 9/15/20239,380,000 shares $402.50 million +1.0%6.7%10.1 $42.91Trump’s Bitcoin Reserve is No Accident… (Ad)Bryce Paul believes this is the #1 coin to buy right now The catalyst behind this surge is a massive new blockchain development…Just click here to get all the details on this crypto coin now 8/31/20239,290,000 shares $374.11 million -3.7%6.6%9.7 $40.27 8/15/20239,650,000 shares $386 million +4.8%6.9%7.9 $40.00 7/31/20239,210,000 shares $381.57 million +4.0%6.6%7.3 $41.43 7/15/20238,860,000 shares $376.37 million +2.8%6.4%7 $42.48 6/30/20238,620,000 shares $353.68 million -0.8%6.2%7.2 $41.03 6/15/20238,690,000 shares $362.29 million +33.3%6.2%7.2 $41.69 5/31/20236,520,000 shares $266.67 million -8.3%4.7%5.5 $40.90 5/15/20237,110,000 shares $257.67 million No Change5.1%7.3 $36.24 10/31/20226,860,000 shares $303.21 million -2.0%4.9%6.9 $44.20 10/15/20227,000,000 shares $324.52 million -3.5%5.0%6.9 $46.36 9/30/20227,250,000 shares $320.67 million +6.6%5.2%7.4 $44.23 9/15/20226,800,000 shares $322.93 million +9.2%4.9%7.1 $47.49 8/31/20226,230,000 shares $264.90 million -7.7%4.5%6.8 $42.52 8/15/20226,750,000 shares $299.77 million +10.7%4.8%7.2 $44.41 7/31/20226,100,000 shares $229.12 million +0.5%4.4%6 $37.56 7/15/20226,070,000 shares $238.61 million +5.9%4.3%6.1 $39.31 6/30/20225,730,000 shares $212.12 million +1.4%4.1%5.3 $37.02 6/15/20225,650,000 shares $195.89 million -5.7%4.5%5.1 $34.67 5/31/20225,990,000 shares $218.75 million -16.1%4.3%5.5 $36.52 5/15/20227,140,000 shares $257.61 million +9.2%5.1%6.6 $36.08 4/30/20226,540,000 shares $240.41 million -12.2%4.7%6.1 $36.76 4/15/20227,450,000 shares $305.23 million +3.9%5.3%6.5 $40.97 3/31/20227,170,000 shares $265.58 million -1.7%N/A0 $37.04 3/15/20227,290,000 shares $238.38 million -4.1%5.2%6.6 $32.70 2/28/20227,600,000 shares $253.69 million -18.7%5.4%6.2 $33.38 2/15/20229,350,000 shares $314.72 million -1.8%6.7%7.2 $33.66 1/31/20229,520,000 shares $302.74 million +31.9%6.8%7.7 $31.80 1/15/20227,220,000 shares $238.84 million -1.5%N/A0 $33.08 12/31/20217,330,000 shares $223.05 million -0.8%5.3%6.4 $30.43 12/15/20217,390,000 shares $229.90 million +8.2%5.3%6.6 $31.11 11/30/20216,830,000 shares $181.00 million +10.3%4.9%6.4 $26.50 11/15/20216,190,000 shares $202.97 million -10.4%4.4%6.4 $32.79 10/29/20216,910,000 shares $220.22 million +1.9%5.0%7.5 $31.87 10/15/20216,780,000 shares $237.98 million +2.1%4.9%7.4 $35.10 9/30/20216,640,000 shares $222.71 million -7.4%4.8%7.7 $33.54 9/15/20217,170,000 shares $265.00 million -6.8%5.1%7.3 $36.96 8/31/20217,690,000 shares $305.75 million -8.5%5.5%7.7 $39.76 8/13/20218,400,000 shares $333.31 million -8.6%6.0%6.4 $39.68 7/30/20219,190,000 shares $341.32 million +7.2%6.6%6.1 $37.14 7/15/20218,570,000 shares $305.69 million -4.8%6.4%5.1 $35.67 6/30/20219,000,000 shares $359.01 million +0.3%6.7%5.3 $39.89 6/15/20218,970,000 shares $329.02 million -17.3%6.7%4.9 $36.68 5/28/202110,850,000 shares $404.16 million +1.0%8.1%5.7 $37.25 5/14/202110,740,000 shares $401.35 million +4.2%8.0%6.6 $37.37 4/30/202110,310,000 shares $446.63 million +6.7%7.7%7.1 $43.32 4/15/20219,660,000 shares $404.08 million +10.2%N/A7.5 $41.83 3/31/20218,770,000 shares $392.11 million +2.2%6.5%7.1 $44.71 3/15/20218,580,000 shares $454.65 million +0.9%6.4%7.3 $52.99 2/26/20218,500,000 shares $453.99 million +7.1%6.3%7.9 $53.41 2/12/20217,940,000 shares $460.12 million +5.2%6.0%7.4 $57.95Trump’s treachery (Ad)Trump’s Final Reset Inside the shocking plot to re-engineer America’s financial system…and why you need to move your money now.Millions of Americans are about to be wiped out, while others could make a fortune… click here to ma 1/29/20217,550,000 shares $458.21 million +2.6%5.7%6.9 $60.69 1/15/20217,360,000 shares $451.54 million -5.4%5.5%6.8 $61.35 12/31/20207,780,000 shares $445.02 million +7.8%5.9%6.8 $57.20 12/15/20207,220,000 shares $345.33 million +2.1%5.4%6.1 $47.83 11/30/20207,070,000 shares $361.49 million +4.1%5.3%6.7 $51.13 11/15/20206,790,000 shares $350.16 million -5.7%5.1%6.9 $51.57 10/30/20207,200,000 shares $337.32 million -11.8%5.4%7.6 $46.85 10/15/20208,160,000 shares $389.31 million +0.1%6.2%8.9 $47.71 9/30/20208,150,000 shares $386.72 million +3.0%6.1%9.8 $47.45 9/15/20207,910,000 shares $418.68 million +4.1%6.0%10.2 $52.93 8/31/20207,600,000 shares $414.20 million -0.7%5.7%10.4 $54.50 8/14/20207,650,000 shares $403.77 million -6.0%5.8%10 $52.78 7/31/20208,140,000 shares $468.54 million -4.6%6.1%10.3 $57.56 7/15/20208,530,000 shares $524.60 million -1.2%6.4%10.6 $61.50 6/30/20208,630,000 shares $508.82 million -5.8%6.5%10.4 $58.96 6/15/20209,160,000 shares $524.04 million +4.0%6.9%10.6 $57.21 5/29/20208,810,000 shares $495.21 million +4.6%6.7%9.4 $56.21 IONS Short Interest - Frequently Asked Questions What is Ionis Pharmaceuticals' current short interest? Short interest is the volume of Ionis Pharmaceuticals shares that have been sold short but have not yet been closed out or covered. As of April 30th, traders have sold 14,630,000 shares of IONS short. 9.45% of Ionis Pharmaceuticals' shares are currently sold short. Learn More on Ionis Pharmaceuticals' current short interest. What is a good short interest ratio for Ionis Pharmaceuticals? The short interest ratio, also known as the "days to cover ratio", is calculated by dividing the number of shares of a stock sold short divided by its average trading volume. A short interest ratio ranging between 1 and 4 generally indicates strong positive sentiment about a stock and a lack of short sellers. A short interest ratio of 10 or greater indicates strong pessimism about a stock. IONS shares currently have a short interest ratio of 8.0. Learn More on Ionis Pharmaceuticals's short interest ratio. Which institutional investors are shorting Ionis Pharmaceuticals? As of the most recent reporting period, the following institutional investors, funds, and major shareholders have reported short positions of Ionis Pharmaceuticals: Jane Street Group LLC, Royal Bank of Canada, Caption Management LLC, Twin Tree Management LP, Torno Capital LLC, Walleye Trading LLC, Walleye Capital LLC, Simplex Trading LLC, Wolverine Asset Management LLC, Citigroup Inc., and DCF Advisers LLC. These positions are disclosed in Form 13F filings with the Securities and Exchange Commission. What is a good short interest percentage for Ionis Pharmaceuticals? Companies that have a short interest as a percentage of float below 10% indicates positive investor sentiment and few short sellers. Stocks with a short interest percentage above 10% is considered high, suggesting some investors are pessimistic about the stock. Companies with a short interest percentage of 20% or more indicates widespread negative sentiment. 9.45% of Ionis Pharmaceuticals' floating shares are currently sold short. Is Ionis Pharmaceuticals' short interest increasing or decreasing? Ionis Pharmaceuticals saw a increase in short interest during the month of April. As of April 30th, there was short interest totaling 14,630,000 shares, an increase of 0.5% from the previous total of 14,550,000 shares. Changes in short volume can be used to identify positive and negative investor sentiment. Investors that short sell a stock are betting that its price will decline in the future. An increase in short sale volume suggests bearish (negative) sentiment among investors. A decrease on short sale volume suggests bullish (positive) sentiment. What is Ionis Pharmaceuticals' float size? Ionis Pharmaceuticals currently has issued a total of 159,159,000 shares. Some of Ionis Pharmaceuticals' outstanding shares are available for trading, while others are subject to various restrictions. The public float, also referred to as floating shares or "the float", are shares that publicly owned, unrestricted and available to trade on the open market. Ionis Pharmaceuticals currently has a public float of 154,750,000 shares. How does Ionis Pharmaceuticals' short interest compare to its competitors? 9.45% of Ionis Pharmaceuticals' shares are currently sold short. Here is how the short interest of companies in the industry of "biotechnology" compare to Ionis Pharmaceuticals: Biogen Inc. (2.18%), United Therapeutics Co. (4.45%), Neurocrine Biosciences, Inc. (4.54%), Incyte Co. (3.36%), BioMarin Pharmaceutical Inc. (2.35%), Exelixis, Inc. (7.20%), Exact Sciences Co. (5.36%), Halozyme Therapeutics, Inc. (7.76%), Repligen Co. (6.48%), Madrigal Pharmaceuticals, Inc. (18.47%), Which stocks are the most shorted right now? As of the most recent reporting period, the following stocks had the largest short interest positions: Spotify Technology S.A. ($4.67 billion), Charter Communications, Inc. ($4.58 billion), Capital One Financial Co. ($4.47 billion), The Kroger Co. ($2.56 billion), Reddit, Inc. ($2.23 billion), Rivian Automotive, Inc. ($2.16 billion), Live Nation Entertainment, Inc. ($1.90 billion), SoFi Technologies, Inc. ($1.85 billion), Zscaler, Inc. ($1.75 billion), and Omnicom Group Inc. ($1.75 billion). View all of the most shorted stocks. What does it mean to sell short Ionis Pharmaceuticals stock? Short selling IONS is an investing strategy that aims to generate trading profit from Ionis Pharmaceuticals as its price is falling. IONS shares are trading down $0.99 today. To short a stock, an investor borrows shares, sells them and buys the shares back on the public market later to return it to the lender. Short sellers are betting that a stock will decline in price. If the stock does drop after selling, the short seller buys it back at a lower price and returns it to the lender. The difference between the sell price and the buy price is the trader's profit. How does a short squeeze work against Ionis Pharmaceuticals? A short squeeze for Ionis Pharmaceuticals occurs when it has a large amount of short interest and its stock appreciates in price. This forces short sellers to cover their short interest positions by buying actual shares of IONS, which in turn drives the price of the stock up even further. How often is Ionis Pharmaceuticals' short interest reported? Short interest is typically published by a stock exchange once per month. However, NASDAQ publishes a report for U.S. stocks, including IONS, twice per month. The most recent reporting period available is April, 30 2025. More Short Interest Resources from MarketBeat Related Companies BIIB Short Interest UTHR Short Interest NBIX Short Interest INCY Short Interest BMRN Short Interest EXEL Short Interest EXAS Short Interest HALO Short Interest RGEN Short Interest MDGL Short Interest Short Interest Tools Stocks to Short Largest Short Interest Positions Short Interest Increases Short Interest Decreases Short Interest Reporting Dates This page (NASDAQ:IONS) was last updated on 5/21/2025 by MarketBeat.com Staff From Our PartnersMarket Panic: Trump Just Dropped a Bomb on Your Stockstock Market Panic: Trump Just Dropped a Bomb on Your Stocks The market is in freefall—and Trump's new tarif...American Alternative | SponsoredGold Hits New Highs as Global Markets SpiralWhen Trump took office in 2017, gold was just $1,100 an ounce. By the time he left, it had soared to $1,839. ...Premier Gold Co | SponsoredWhite House to reset Social Security?Elon Musk's parting DOGE gift looks set to shock America... 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