Alnylam Pharmaceuticals (ALNY) Short Interest Ratio & Short Volume $446.51 -5.82 (-1.29%) Closing price 08/29/2025 04:00 PM EasternExtended Trading$446.62 +0.11 (+0.02%) As of 08/29/2025 05:37 PM Eastern Extended trading is trading that happens on electronic markets outside of regular trading hours. This is a fair market value extended hours price provided by Polygon.io. Learn more. Add Compare Share Share Short Interest Stock AnalysisAnalyst ForecastsChartCompetitorsEarningsFDA EventsFinancialsHeadlinesInsider TradesOptions ChainOwnershipSEC FilingsShort InterestSustainabilityTrendsBuy This Stock Alnylam Pharmaceuticals Short Interest DataAlnylam Pharmaceuticals (ALNY) has a short interest of 3.24 million shares, representing 2.51% of the float (the number of shares available for trading by the public). This marks a -4.14% decrease in short interest from the previous month. The short interest ratio (days to cover) is 3.2, indicating that it would take 3.2 days of the average trading volume of 1.19 million shares to cover all short positions.Current Short Interest3,240,000 sharesPrevious Short Interest3,380,000 sharesChange Vs. Previous Month-4.14%Dollar Volume Sold Short$1.27 billionShort Interest Ratio3.2 Days to CoverLast Record DateJuly 31, 2025Outstanding Shares131,080,000 sharesShort Percent of Float2.51%Today's Trading Volume827,614 sharesAverage Trading Volume1,190,821 sharesToday's Volume Vs. Average69% Short Selling Alnylam Pharmaceuticals? Sign up to receive the latest short interest report for Alnylam Pharmaceuticals and its competitors with MarketBeat's FREE newsletter. Email Address Get Report View SMS TermsBy entering your phone number and clicking the sign-up button, you agree to receive periodic text messages from MarketBeat at the phone number you submitted, including texts that may be sent using an automatic telephone dialing system. 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Skip Charts & View Short Interest HistoryShort Interest ChartDays to Cover ChartShort Percent of Float ChartALNY Short Interest Over TimeALNY Days to Cover Over TimeALNY Percentage of Float Shorted Over Time Alnylam 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 7/31/20253,240,000 shares $1.27 billion -4.1%2.5%3.2 $392.24 7/15/20253,380,000 shares $1.05 billion +1.5%N/A3.6 $311.12 6/30/20253,330,000 shares $1.09 billion -1.5%2.6%3.4 $326.09 6/15/20253,380,000 shares $1.04 billion -2.0%2.6%3.4 $307.99 5/31/20253,450,000 shares $1.05 billion -6.3%2.7%3.3 $304.59 5/15/20253,680,000 shares $1.04 billion +16.8%2.9%3.7 $283.40 4/30/20253,150,000 shares $829.21 million +2.9%N/A3.3 $263.24 4/15/20253,060,000 shares $706.65 million +2.3%2.4%3.4 $230.93 3/31/20252,990,000 shares $807.36 million +17.7%2.3%3.5 $270.02 3/15/20252,540,000 shares $614.07 million +2.0%2.0%3.4 $241.76 Get the Latest News and Ratings for ALNY and Related StocksEnter your email address below to receive the latest news and analysts' ratings for Alnylam Pharmaceuticals and its competitors with MarketBeat's FREE daily newsletter. 2/28/20252,490,000 shares $614.41 million -22.7%2.0%3.7 $246.75 2/15/20253,220,000 shares $825.77 million +9.5%2.5%4.8 $256.45 1/31/20252,940,000 shares $797.65 million -6.7%N/A4.2 $271.31 1/15/20253,150,000 shares $790.68 million -6.0%N/A4.2 $251.01 12/31/20243,350,000 shares $788.29 million -4.0%N/A4.4 $235.31 12/15/20243,490,000 shares $856.59 million +3.0%N/A4.5 $245.44 11/30/20243,390,000 shares $857.91 million -9.4%N/A4.4 $253.07 11/15/20243,740,000 shares $880.99 million +1.1%N/A4.3 $235.56 10/31/20243,700,000 shares $986.38 million -23.6%N/A4.6 $266.59 10/15/20244,840,000 shares $1.39 billion +7.3%N/A5.8 $287.36 9/30/20244,510,000 shares $1.24 billion +1.4%N/A5.5 $275.03 9/15/20244,450,000 shares $1.18 billion +18.0%N/A3.8 $265.27 8/31/20243,770,000 shares $990.34 million -16.6%N/A3.1 $262.69 8/15/20244,520,000 shares $1.19 billion +4.4%N/A4 $262.70 7/31/20244,330,000 shares $1.03 billion -3.6%N/A4 $237.46 7/15/20244,490,000 shares $1.15 billion +22.0%N/A4.5 $256.18 6/30/20243,680,000 shares $894.24 million +72.8%N/A3.9 $243.00 6/15/20242,130,000 shares $341.63 million -14.1%N/A2.6 $160.39 5/31/20242,480,000 shares $368.11 million -2.4%N/A4.4 $148.43 5/15/20242,540,000 shares $374.40 million -3.4%N/A4.3 $147.40 4/30/20242,630,000 shares $378.59 million +5.2%N/A3.2 $143.95 4/15/20242,500,000 shares $369.25 million -10.7%N/A3 $147.70 3/31/20242,800,000 shares $418.46 million +4.1%N/A3.3 $149.45 3/15/20242,690,000 shares $401.54 million -11.5%N/A3.2 $149.27 2/29/20243,040,000 shares $459.31 million -23.8%N/A3.6 $151.09 2/15/20243,990,000 shares $588.25 million -0.5%N/A5 $147.43 1/31/20244,010,000 shares $693.37 million -7.4%N/A6.5 $172.91 1/15/20244,330,000 shares $837.38 million -8.5%N/A7.4 $193.39 12/31/20234,730,000 shares $905.37 million -5.2%N/A7.6 $191.41 12/15/20234,990,000 shares $924.35 million -2.0%N/A7.8 $185.24He Called Nvidia at $1.10. Now, He Says THIS Stock Will… (Ad)A Millionaire With SEVEN Clicks? $1,000 in just seven stocks in 2004 could have turned into a million-dollar portfolio today… Back then… one financial expert begged people to look at Nvidia -- when it was trading at just $1.10! Now… he’s urging you to look at a new group of seven stocks…Check this Out (The NEXT Magnificent Seven) 11/30/20235,090,000 shares $856.39 million -1.9%N/A7.6 $168.25 11/15/20235,190,000 shares $887.75 million -1.5%N/A8 $171.05 10/31/20235,270,000 shares $799.99 million -1.7%N/A8.3 $151.80 10/15/20235,360,000 shares $901.12 million +3.9%N/A8.7 $168.12 9/30/20235,160,000 shares $913.84 million +0.2%N/A8.6 $177.10 9/15/20235,150,000 shares $952.70 million -2.8%N/A9 $184.99 8/31/20235,300,000 shares $1.05 billion -1.5%N/A9.9 $197.82 8/15/20235,380,000 shares $969.10 million +1.7%N/A10.2 $180.13 7/31/20235,290,000 shares $1.03 billion +6.9%N/A9.7 $195.40 7/15/20234,950,000 shares $975.65 million -0.6%N/A8.4 $197.10 6/30/20234,980,000 shares $945.90 million +0.4%N/A8 $189.94 6/15/20234,960,000 shares $1.00 billion -1.8%N/A7.4 $202.34 5/31/20235,050,000 shares $934.30 million -1.4%N/A7 $185.01 5/15/20235,120,000 shares $1.06 billion +0.8%N/A6.3 $206.20 4/30/20235,080,000 shares $1.01 billion +2.2%N/A6.2 $199.20 4/15/20234,970,000 shares $1.01 billion -4.1%N/A6 $203.92 3/31/20235,180,000 shares $1.04 billion +5.1%N/A6.4 $200.32 3/15/20234,930,000 shares $915.75 million -8.5%N/A6.3 $185.75 2/28/20235,390,000 shares $1.03 billion +5.7%N/A7 $191.45 2/15/20235,100,000 shares $1.13 billion -4.3%N/A6.5 $222.10 1/31/20235,330,000 shares $1.21 billion -6.2%N/A7.1 $226.40 1/15/20235,680,000 shares $1.34 billion +11.2%N/A7.3 $235.53 12/30/20225,110,000 shares $1.21 billion -5.4%N/A6.2 $237.65 12/15/20225,400,000 shares $1.24 billion +8.2%N/A6.1 $229.37 11/30/20224,990,000 shares $1.10 billion -10.3%N/A5.1 $220.59 11/15/20225,560,000 shares $1.19 billion -7.8%N/A5.7 $214.29 10/31/20226,030,000 shares $1.25 billion +25.6%N/A6.1 $207.26 10/15/20224,800,000 shares $890.54 million +5.7%N/A4.2 $185.53 9/30/20224,540,000 shares $908.73 million +3.7%N/A4.2 $200.16 9/15/20224,380,000 shares $913.14 million +4.3%N/A4.2 $208.48 8/31/20224,200,000 shares $868.01 million -16.0%N/A4 $206.67 8/15/20225,000,000 shares $1.16 billion +1.4%N/A5.2 $231.01 7/31/20224,930,000 shares $700.26 million -1.2%N/A4.9 $142.04 7/15/20224,990,000 shares $725.50 million +4.2%N/A5.8 $145.39 6/30/20224,790,000 shares $698.62 million +1.1%N/A5.5 $145.85 6/15/20224,740,000 shares $642.03 million -15.7%5.0%5.4 $135.45 5/31/20225,620,000 shares $707.00 million -4.1%N/A6.8 $125.80 5/15/20225,860,000 shares $741.11 million -1.0%N/A6.7 $126.47 4/30/20225,920,000 shares $789.91 million +2.3%N/A7 $133.43 4/15/20225,790,000 shares $968.90 million +11.8%N/A7.1 $167.34 3/31/20225,180,000 shares $845.84 million +9.5%N/A6.4 $163.29 3/15/20224,730,000 shares $723.31 million +3.7%N/A5.4 $152.92 2/28/20224,560,000 shares $719.80 million +3.9%N/A5.2 $157.85 2/15/20224,390,000 shares $672.99 million +8.1%N/A5.3 $153.30 1/31/20224,060,000 shares $558.66 million +2.8%3.6%5.1 $137.60 1/15/20223,950,000 shares $586.58 million +11.9%N/A4.8 $148.50 12/31/20213,530,000 shares $598.62 million -6.1%N/A4.6 $169.58 12/15/20213,760,000 shares $718.39 million -4.8%N/A5.1 $191.06 11/30/20213,950,000 shares $726.01 million -2.5%N/A6.5 $183.80 11/15/20214,050,000 shares $701.91 million +4.9%N/A6.8 $173.31He Called Nvidia at $1.10. Now, He Says THIS Stock Will… (Ad)A Millionaire With SEVEN Clicks? $1,000 in just seven stocks in 2004 could have turned into a million-dollar portfolio today… Back then… one financial expert begged people to look at Nvidia -- when it was trading at just $1.10! Now… he’s urging you to look at a new group of seven stocks…Check this Out (The NEXT Magnificent Seven) 10/29/20213,860,000 shares $615.90 million -0.5%N/A6.4 $159.56 10/15/20213,880,000 shares $809.21 million -3.2%N/A7.1 $208.56 9/30/20214,010,000 shares $757.13 million -9.3%N/A6.7 $188.81 9/15/20214,420,000 shares $828.66 million -8.5%N/A7 $187.48 8/31/20214,830,000 shares $972.91 million -3.6%N/A7.2 $201.43 8/13/20215,010,000 shares $984.67 million -1.0%N/A7.3 $196.54 7/30/20215,060,000 shares $905.44 million +19.9%N/A7.7 $178.94 7/15/20214,220,000 shares $725.63 million -2.3%3.6%6.8 $171.95 6/30/20214,320,000 shares $732.33 million -6.7%3.7%7.2 $169.52 6/15/20214,630,000 shares $770.90 million +9.2%4.0%8.7 $166.50 5/28/20214,240,000 shares $602.04 million -6.2%3.7%8.6 $141.99 5/14/20214,520,000 shares $600.80 million +9.4%N/A9.1 $132.92 4/30/20214,130,000 shares $576.92 million +0.7%N/A7.7 $139.69 4/15/20214,100,000 shares $567.07 million +12.3%N/A7 $138.31 3/31/20213,650,000 shares $493.22 million -1.9%N/A5.3 $135.13 3/15/20213,720,000 shares $528.98 million +0.5%N/A5.2 $142.20 2/26/20213,700,000 shares $542.38 million +5.1%N/A5.4 $146.59 2/12/20213,520,000 shares $582.14 million -4.9%N/A5.2 $165.38 1/29/20213,700,000 shares $572.54 million -4.4%N/A5.4 $154.74 1/15/20213,870,000 shares $638.82 million +10.9%N/A5.9 $165.07 12/31/20203,490,000 shares $457.33 million -4.6%N/A6.4 $131.04 12/15/20203,660,000 shares $485.65 million -3.2%N/A7.2 $132.69 11/30/20203,780,000 shares $490.87 million +1.3%N/A7.4 $129.86 11/15/20203,730,000 shares $505.45 million +3.9%N/A7.2 $135.51 10/30/20203,590,000 shares $442.72 million +5.9%N/A7.5 $123.32 10/15/20203,390,000 shares $487.85 million +4.0%N/A7.3 $143.91 9/30/20203,260,000 shares $474.66 million -9.2%N/A6.6 $145.60 9/15/20203,590,000 shares $468.53 million -10.7%N/A6.2 $130.51 ALNY Short Interest - Frequently Asked Questions What is Alnylam Pharmaceuticals' current short interest? Short interest is the volume of Alnylam Pharmaceuticals shares that have been sold short but have not yet been covered or closed out. As of July 31st, investors have sold 3,240,000 shares of ALNY short. 2.51% of Alnylam Pharmaceuticals' shares are currently sold short. Learn More on Alnylam Pharmaceuticals' current short interest. What is a good short interest ratio for Alnylam 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. ALNY shares currently have a short interest ratio of 3.0. Learn More on Alnylam Pharmaceuticals's short interest ratio. Which institutional investors are shorting Alnylam Pharmaceuticals? As of the most recent reporting period, the following institutional investors, funds, and major shareholders have reported short positions of Alnylam Pharmaceuticals: LMR Partners LLP, Group One Trading LLC, 683 Capital Management LLC, Jane Street Group LLC, Volterra Technologies LP, Diadema Partners LP, Qube Research & Technologies Ltd, Walleye Capital LLC, Walleye Trading LLC, Arrowpoint Investment Partners Singapore Pte. Ltd., JPMorgan Chase & Co., Persistent Asset Partners Ltd, Garda Capital Partners LP, Mirae Asset Securities USA Inc., Portman Square Capital LLP, 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 Alnylam 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. 2.51% of Alnylam Pharmaceuticals' floating shares are currently sold short. Is Alnylam Pharmaceuticals' short interest increasing or decreasing? Alnylam Pharmaceuticals saw a decrease in short interest in the month of July. As of July 31st, there was short interest totaling 3,240,000 shares, a decrease of 4.1% from the previous total of 3,380,000 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. How does Alnylam Pharmaceuticals' short interest compare to its competitors? 2.51% of Alnylam Pharmaceuticals' shares are currently sold short. Here is how the short interest of companies in the industry of "biotechnology" compare to Alnylam Pharmaceuticals: Amgen Inc. (2.33%), Gilead Sciences, Inc. (1.61%), Vertex Pharmaceuticals Incorporated (1.71%), Regeneron Pharmaceuticals, Inc. (2.24%), 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%), 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 Alnylam Pharmaceuticals stock? Short selling ALNY is an investing strategy that aims to generate trading profit from Alnylam Pharmaceuticals as its price is falling. ALNY shares are trading down $5.82 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 Alnylam Pharmaceuticals? A short squeeze for Alnylam 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 ALNY, which in turn drives the price of the stock up even further. How often is Alnylam 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 ALNY, twice per month. The most recent reporting period available is July, 31 2025. More Short Interest Resources from MarketBeat Related Companies Amgen Short Interest Gilead Sciences Short Interest Vertex Pharmaceuticals Short Interest Regeneron Pharmaceuticals Short Interest Biogen Short Interest Incyte Short Interest United Therapeutics Short Interest Neurocrine Biosciences Short Interest BioMarin Pharmaceutical Short Interest Exelixis 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:ALNY) was last updated on 9/1/2025 by MarketBeat.com Staff From Our PartnersRetire Comfortably with These New Monthly Income ETFs?Too many retirees lie awake at night, worried their savings won’t last. 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