Ionis Pharmaceuticals (IONS) Short Interest Ratio & Short Volume $42.59 -0.65 (-1.51%) As of 02:12 PM Eastern This is a fair market value price provided by Polygon.io. Learn more. Add Compare Share Share Short Interest Stock AnalysisAnalyst ForecastsChartCompetitorsEarningsFDA EventsFinancialsHeadlinesInsider TradesOptions ChainOwnershipSEC FilingsShort InterestSustainabilityTrendsBuy This Stock Ionis Pharmaceuticals Short Interest DataIonis Pharmaceuticals (IONS) has a short interest of 11.58 million shares, representing 7.45% of the float (the number of shares available for trading by the public). This marks a -10.16% decrease in short interest from the previous month. The short interest ratio (days to cover) is 6.5, indicating that it would take 6.5 days of the average trading volume of 1.76 million shares to cover all short positions.Current Short Interest11,580,000 sharesPrevious Short Interest12,890,000 sharesChange Vs. Previous Month-10.16%Dollar Volume Sold Short$497.71 millionShort Interest Ratio6.5 Days to CoverLast Record DateJuly 31, 2025Outstanding Shares159,390,000 sharesFloat Size155,530,000 sharesShort Percent of Float7.45%Today's Trading Volume973,761 sharesAverage Trading Volume1,760,601 sharesToday's Volume Vs. Average55% 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 7/31/202511,580,000 shares $497.71 million -10.2%7.5%6.5 $42.98 7/15/202512,890,000 shares $541.38 million -8.8%8.3%7.6 $42.00 6/30/202514,140,000 shares $558.67 million -0.6%9.1%8 $39.51 6/15/202514,230,000 shares $506.45 million -4.1%9.2%8.4 $35.59 5/31/202514,840,000 shares $499.22 million -2.8%9.6%8.9 $33.64 5/15/202515,270,000 shares $503.76 million +4.4%9.8%9.3 $32.99 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 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. 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 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 $49.70Cover all your expenses with just $118,000 invested? (Ad)Generate up to $5,000/month with 10X less money? That's what every financial advisor tells you. But I just discovered a new way to do it with 10X less money.Start collecting this income (next payout coming soon) 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 $42.91 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 $37.37Cover all your expenses with just $118,000 invested? (Ad)Generate up to $5,000/month with 10X less money? That's what every financial advisor tells you. But I just discovered a new way to do it with 10X less money.Start collecting this income (next payout coming soon) 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 $57.95 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 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 covered or closed out. As of July 31st, investors have sold 11,580,000 shares of IONS short. 7.45% 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 6.0. 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: Nomura Holdings Inc., Group One Trading LLC, Jane Street Group LLC, Caption Management LLC, Walleye Capital LLC, Walleye Trading LLC, Simplex Trading LLC, Wolverine Asset Management LLC, and Twin Tree Management LP. 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. 7.45% of Ionis Pharmaceuticals' floating shares are currently sold short. Is Ionis Pharmaceuticals' short interest increasing or decreasing? Ionis Pharmaceuticals saw a drop in short interest in July. As of July 31st, there was short interest totaling 11,580,000 shares, a drop of 10.2% from the previous total of 12,890,000 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 159,390,000 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 155,530,000 shares. How does Ionis Pharmaceuticals' short interest compare to its competitors? 7.45% 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. (2.71%), Incyte Corporation (3.85%), United Therapeutics Corporation (3.56%), Neurocrine Biosciences, Inc. (3.02%), BioMarin Pharmaceutical Inc. (2.71%), Exelixis, Inc. (6.67%), Madrigal Pharmaceuticals, Inc. (22.84%), Exact Sciences Corporation (3.68%), Halozyme Therapeutics, Inc. (8.58%), Repligen Corporation (6.84%), Which stocks are the most shorted right now? As of the most recent reporting period, the following stocks had the largest short interest positions: SPDR S&P 500 ETF Trust ($70.87 billion), Invesco QQQ ($30.12 billion), iShares Russell 2000 ETF ($19.85 billion), iShares 20+ Year Treasury Bond ETF ($10.34 billion), Strategy Inc ($8.98 billion), iShares iBoxx $ Investment Grade Corporate Bond ETF ($7.61 billion), SPDR S&P Biotech ETF ($6.81 billion), Invesco S&P 500 Equal Weight ETF ($6.14 billion), Palo Alto Networks, Inc. ($5.97 billion), and Super Micro Computer, Inc. ($5.28 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 $1.06 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 July, 31 2025. More Short Interest Resources from MarketBeat Related Companies BIIB Short Interest INCY Short Interest UTHR Short Interest NBIX Short Interest BMRN Short Interest EXEL Short Interest MDGL Short Interest EXAS Short Interest HALO Short Interest RGEN 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 8/22/2025 by MarketBeat.com Staff From Our PartnersTrump’s betrayal exposedTrump’s Final Reset Inside the shocking plot to re-engineer America’s financial system…and why you need to ...Porter & Company | SponsoredSilver’s Still Under $35… For Now.Silver is trading around $33—but insiders are betting on a $70 breakout by year’s end. With supply shrinkin...GoldenCrest Metals | SponsoredWhat Steve Bannon revealed about Trump’s gold playA Trump advisor just said 3 words that could reset the dollar. It’s a gold move nobody saw coming—and your ...Reagan Gold Group | SponsoredGENIUS Act: Cancel Your Money?A new law called the GENIUS Act could quietly trigger the most radical shift in American finance in decades. B...Priority Gold | SponsoredThe Trump Dump is starting; Get out of stocks now?The first 365 days of the Trump presidency… Will be the best time to get rich in American history.Paradigm Press | SponsoredEveryone’s watching Nvidia right now. Here’s why I’m excited.So, unless you’ve been living under a rock, you probably saw the news… Nvidia just signed a $7 BILLION deal...Timothy Sykes | SponsoredREVEALED FREE: Our top 3 stocks to own in 2025 and beyondEvery time Weiss Ratings flashed green like this, the average gain on each and every stock has been 303% (incl...Weiss Ratings | SponsoredBREAKING: The House just passed 3 pro-crypto bills!The “top secret” DeFi play Our #1 Coin Report reveals which protocol is building this institutional bridge...Crypto 101 Media | Sponsored Adding Choose a watchlist: Watchlist Adding You have already added ten stocks to your watchlist. Upgrade to MarketBeat All Access to add more stocks to your watchlist. Adding Ionis Pharmaceuticals, Inc. Please log in to your account or sign up in order to add this asset to your watchlist. Share Ionis Pharmaceuticals With A Colleague Link copied to clipboard. Get 30 Days of MarketBeat All Access for Free Sign up for MarketBeat All Access to gain access to MarketBeat's full suite of research tools. Start Your 30-Day Trial MarketBeat All Access Features Best-in-Class Portfolio Monitoring Get personalized stock ideas. Compare portfolio to indices. Check stock news, ratings, SEC filings, and more. Stock Ideas and Recommendations See daily stock ideas from top analysts. Receive short-term trading ideas from MarketBeat. Identify trending stocks on social media. Advanced Stock Screeners and Research Tools Use our seven stock screeners to find suitable stocks. Stay informed with MarketBeat's real-time news. Export data to Excel for personal analysis. Sign in to your free account to enjoy these benefits In-depth profiles and analysis for 20,000 public companies. Real-time analyst ratings, insider transactions, earnings data, and more. Our daily ratings and market update email newsletter. Sign in to your free account to enjoy all that MarketBeat has to offer. Sign In Create Account Your Email Address: Email Address Required Your Password: Password Required Log In or Sign in with Facebook Sign in with Google Forgot your password? Your Email Address: Please enter your email address. Please enter a valid email address Choose a Password: Please enter your password. Your password must be at least 8 characters long and contain at least 1 number, 1 letter, and 1 special character. Create My Account (Free) or Sign in with Facebook Sign in with Google By creating a free account, you agree to our terms of service. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
MarketBeat All Access