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Alnylam Pharmaceuticals (ALNY) Short Interest Ratio & Short Volume

Alnylam Pharmaceuticals logo
$236.22 +6.92 (+3.02%)
As of 08/21/2026 04:00 PM Eastern
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Alnylam Pharmaceuticals Short Interest Overview

As of July 31, 2026, Alnylam Pharmaceuticals (ALNY) had a short interest of 4.80 million shares sold short, representing 3.62% of the public float. This marks a -16.80% decrease in short interest since the prior report. The short interest ratio (days to cover) is 2.2, meaning it would take 2.2 days of the average trading volume of 2.35 million shares to cover all short positions.

Current Short Interest
4,803,194 shares
Previous Short Interest
5,773,373 shares
Change Vs. Previous Month
-16.80%
Dollar Volume Sold Short
$987.15 million
Short Interest Ratio
2.2 Days to Cover
Last Record Date
July 31, 2026
Outstanding Shares
133,809,000 shares
Short Percent of Float
3.62%
Today's Trading Volume
1,902,236 shares
Average Trading Volume
2,351,337 shares
Today's Volume Vs. Average
81%
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Short Interest ChartDays to Cover ChartShort Percent of Float Chart

ALNY Short Interest Over Time

ALNY Days to Cover Over Time

ALNY Percentage of Float Shorted Over Time

Alnylam Pharmaceuticals Tesla Short Interest History & Recent Changes

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Report DateTotal Shares Sold ShortDollar Volume Sold ShortChange from Previous ReportPercentage of Float ShortedDays to CoverPrice on Report Date
7/31/20264,803,194 shares $987.15 million -16.8%3.6%2.18 $205.52
7/15/20265,773,373 shares $1.61 billion -0.5%4.4%3.24 $279.14
6/30/20265,799,788 shares $1.75 billion +6.7%4.4%4.22 $301.03
6/15/20265,437,337 shares $1.56 billion +2.6%4.1%4.76 $287.80
5/29/20265,300,015 shares $1.60 billion -1.8%4.0%5.78 $301.98
5/15/20265,398,804 shares $1.55 billion +13.1%4.1%5.13 $286.98
4/30/20264,773,214 shares $1.48 billion -5.2%3.6%4.02 $309.49
4/15/20265,034,063 shares $1.68 billion -0.4%3.8%5.12 $333.39
3/31/20265,056,408 shares $1.67 billion +15.7%3.8%4.01 $330.71
3/13/20264,369,615 shares $1.37 billion -4.4%3.3%4.18 $313.41
2/27/20264,572,652 shares $1.52 billion -12.8%3.5%4.46 $332.92
2/13/20265,244,475 shares $1.65 billion -0.7%4.0%2.8 $314.40
1/30/20265,282,136 shares $1.79 billion -5.1%4.0%3.66 $338.06
1/15/20265,565,961 shares $2.00 billion +0.6%4.3%3.72 $359.18
12/31/20255,532,159 shares $2.20 billion +32.2%4.2%2.89 $397.65
12/15/20254,184,652 shares $1.64 billion +5.7%3.2%3.19 $391.50
11/28/20253,960,190 shares $1.79 billion -7.5%3.0%4.09 $451.27
11/14/20254,279,250 shares $1.92 billion +13.5%3.3%4.49 $449.16
10/31/20253,769,098 shares $1.72 billion -5.6%2.9%3.34 $456.04
10/15/20253,990,000 shares $1.88 billion +13.7%3.1%3.4 $470.27
9/30/20253,510,000 shares $1.60 billion -5.7%N/A3.1 $456.00
9/15/20253,720,000 shares $1.72 billion -6.3%N/A3.3 $461.14
8/31/20253,970,000 shares $1.77 billion +15.7%3.1%3.6 $446.51
8/15/20253,430,000 shares $1.54 billion +5.9%N/A3.2 $448.91
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
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
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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 $185.24
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
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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 $173.31
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

ALNY Short Interest - Frequently Asked Questions

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 4,803,194 shares of ALNY short. 3.62% of Alnylam Pharmaceuticals' shares are currently sold short. Learn More on Alnylam Pharmaceuticals' current short interest.

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 2.2. Learn More on Alnylam Pharmaceuticals's short interest ratio.

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. 3.62% of Alnylam Pharmaceuticals' floating shares are currently sold short.

Alnylam Pharmaceuticals saw a drop in short interest in July. As of July 31st, there was short interest totaling 4,803,194 shares, a drop of 16.8% from the previous total of 5,773,373 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.

3.62% 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: Regeneron Pharmaceuticals, Inc. (3.54%), argenex SE (2.19%), Moderna, Inc. (13.98%), Natera, Inc. (3.21%), Revolution Medicines, Inc. (5.82%), Biogen Inc. (3.70%), BioNTech SE Sponsored ADR (1.21%), Insmed, Inc. (5.31%), Roivant Sciences Ltd. (5.37%), Incyte Corporation (6.03%),

As of the most recent reporting period, the following stocks had the largest short interest positions: SPDR S&P 500 ETF Trust ($70.50 billion), Invesco QQQ ($50.36 billion), iShares Russell 2000 ETF ($21.20 billion), Western Digital Corporation ($13.40 billion), SPDR S&P Biotech ETF ($11.59 billion), Nebius Group N.V. ($11.46 billion), iShares 20+ Year Treasury Bond ETF ($7.84 billion), iShares iBoxx $ High Yield Corporate Bond ETF ($7.51 billion), iShares Semiconductor ETF ($6.37 billion), and Financial Select Sector SPDR Fund ($6.34 billion). View all of the most shorted stocks.

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 up $6.92 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.

A short squeeze for Alnylam Pharmaceuticals occurs when it has a large amount of short interest and its stock increases 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.

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 2026.

Understanding short interest metrics can help you assess how traders are positioning around a stock like ALNY:

  • Shares Sold Short: The total number of shares that have been sold by short sellers but have not yet been covered or closed out. A high number may indicate bearish sentiment.
  • Short Float: The percentage of a company’s publicly available shares (or "float") that are sold short. A higher short float suggests a greater portion of the stock is being bet against.
  • Days to Cover (Short Interest Ratio): This estimates how many days it would take short sellers to cover their positions, based on average daily trading volume. Higher values can signal potential for a short squeeze if buying pressure increases.

These metrics are often used by traders to gauge sentiment, volatility risk, and the potential for price movements based on short covering activity.


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Short Interest Tools

Short interest data for NASDAQ:ALNY is sourced from the Financial Industry Regulatory Authority (FINRA), with the most recent report published on 8/11/2026. FINRA publishes updated short interest twice a month.
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