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iShares Biotechnology ETF (IBB) Short Interest Ratio & Short Volume

iShares Biotechnology ETF logo
$170.00 +0.06 (+0.04%)
As of 04:00 PM Eastern
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iShares Biotechnology ETF Short Interest Overview

As of April 30, 2026, iShares Biotechnology ETF (IBB) had a short interest of 13.27 million shares sold short, representing 28.20% of the public float. This marks a 5.43% increase in short interest since the prior report. The short interest ratio (days to cover) is 9.1, meaning it would take 9.1 days of the average trading volume of 1.37 million shares to cover all short positions.

Current Short Interest
13,267,269 shares
Previous Short Interest
12,584,040 shares
Change Vs. Previous Month
5.43%
Dollar Volume Sold Short
$2.24 billion
Short Interest Ratio
9.1 Days to Cover
Last Record Date
April 30, 2026
Outstanding Shares
47,050,000 shares
Short Percent of Float
28.20%
Today's Trading Volume
1,456,606 shares
Average Trading Volume
1,370,983 shares
Today's Volume Vs. Average
106%
Short Selling iShares Biotechnology ETF?
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Short Interest ChartDays to Cover ChartShort Percent of Float Chart

IBB Short Interest Over Time

IBB Days to Cover Over Time

IBB Percentage of Float Shorted Over Time

iShares Biotechnology ETF 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
4/30/202613,267,269 shares $2.24 billion +5.4%28.2%9.08 $168.69
4/15/202612,584,040 shares $2.21 billion -5.4%26.3%9.39 $175.99
3/31/202613,298,650 shares $2.25 billion -7.1%27.7%7.84 $168.85
3/13/202614,315,391 shares $2.37 billion -3.9%29.4%7.65 $165.51
2/27/202614,892,958 shares $2.61 billion -1.1%30.1%9.32 $175.37
2/13/202615,059,984 shares $2.60 billion +18.4%30.7%6.94 $172.57
1/30/202612,721,468 shares $2.19 billion +0.2%25.8%7.48 $172.43
1/15/202612,700,561 shares $2.17 billion +0.8%25.7%6.17 $170.56
12/31/202512,595,742 shares $2.13 billion -5.9%25.2%8.52 $168.77
12/15/202513,378,601 shares $2.27 billion +9.5%26.8%8.09 $169.38
11/28/202512,218,668 shares $2.12 billion -1.2%24.2%4.09 $173.63
11/14/202512,364,326 shares $2.03 billion +4.8%25.1%4.81 $164.19
10/31/202511,794,089 shares $1.88 billion +0.8%27.4%6.03 $159.38
10/15/202511,700,000 shares $1.79 billion -6.8%28.1%6.4 $153.39
9/30/202512,550,000 shares $1.81 billion +15.9%N/A7.4 $144.37
9/15/202510,830,000 shares $1.52 billion +3.8%N/A6.8 $140.72
8/31/202510,430,000 shares $1.44 billion No Change25.9%6.3 $138.22
5/15/202512,860,000 shares $1.53 billion +15.7%29.4%7.7 $119.24
4/30/202511,120,000 shares $1.41 billion +6.8%N/A6.9 $126.58
4/15/202510,410,000 shares $1.25 billion +7.1%23.6%7.1 $119.85
3/31/20259,720,000 shares $1.24 billion -1.0%21.2%6.7 $127.90
3/15/20259,820,000 shares $1.32 billion +4.8%20.8%7.4 $134.19
2/28/20259,370,000 shares $1.28 billion +2.5%19.8%6.7 $137.03
2/15/20259,140,000 shares $1.25 billion -9.4%19.3%6.4 $136.55
1/31/202510,090,000 shares $1.40 billion -9.2%N/A6.7 $138.66
1/15/202511,110,000 shares $1.48 billion -1.1%N/A7.7 $133.42
12/31/202411,230,000 shares $1.48 billion -3.8%N/A8.4 $132.21
12/15/202411,670,000 shares $1.59 billion +3.6%N/A9 $136.61
11/30/202411,260,000 shares $1.59 billion +9.5%N/A9.1 $141.55
11/15/202410,280,000 shares $1.37 billion +1.4%N/A8.6 $133.38
10/31/202410,140,000 shares $1.42 billion +3.3%N/A9.8 $140.29
10/15/20249,820,000 shares $1.43 billion +1.5%N/A8.8 $145.82
9/30/20249,680,000 shares $1.41 billion +4.1%N/A8 $145.60
9/15/20249,300,000 shares $1.37 billion -8.6%N/A7.4 $147.81
8/31/202410,180,000 shares $1.51 billion +0.4%N/A8.3 $148.17
8/15/202410,140,000 shares $1.47 billion -7.2%N/A7.7 $144.95
7/31/202410,930,000 shares $1.62 billion -10.5%N/A8 $147.97
7/15/202412,210,000 shares $1.77 billion No ChangeN/A8.7 $145.15
1/15/20248,740,000 shares $1.20 billion +4.3%N/A4.6 $137.13
12/31/20238,380,000 shares $1.14 billion -14.1%N/A4.2 $135.85
12/15/20239,760,000 shares $1.29 billion -8.9%N/A4.7 $131.78
11/30/202310,710,000 shares $1.30 billion +5.6%N/A5.5 $120.93
11/15/202310,140,000 shares $1.20 billion -3.9%N/A5.2 $118.03
10/31/202310,550,000 shares $1.20 billion +6.5%N/A5.7 $113.68
10/15/20239,910,000 shares $1.21 billion -2.5%N/A6 $121.63
9/30/202310,160,000 shares $1.24 billion +7.7%N/A6.7 $122.29
9/15/20239,430,000 shares $1.19 billion -7.0%N/A6.6 $126.61
8/31/202310,140,000 shares $1.31 billion -0.4%N/A6.6 $128.71
8/15/202310,180,000 shares $1.30 billion +1.9%N/A6.6 $128.01
7/31/20239,990,000 shares $1.29 billion +2.7%N/A6.3 $129.31
7/15/20239,730,000 shares $1.25 billion -7.3%N/A6 $128.24
6/30/202310,500,000 shares $1.33 billion +0.4%N/A6.5 $126.96
6/15/202310,460,000 shares $1.38 billion +10.2%N/A6.7 $131.81
5/31/20239,490,000 shares $1.20 billion +1.3%N/A6 $126.28
5/15/20239,370,000 shares $1.23 billion -6.4%N/A6 $131.74
4/30/202310,010,000 shares $1.31 billion +2.5%N/A6.4 $130.51
4/15/20239,770,000 shares $1.29 billion -0.8%N/A6.3 $132.43
3/31/20239,850,000 shares $1.27 billion -6.5%N/A6.4 $129.16
3/15/202310,530,000 shares $1.33 billion +12.4%N/A6.7 $126.06
2/28/20239,370,000 shares $1.19 billion -7.0%N/A6.2 $127.18
2/15/202310,070,000 shares $1.35 billion +6.7%N/A6.4 $133.77
1/31/20239,440,000 shares $1.29 billion -4.4%N/A5.6 $136.55
1/15/20239,870,000 shares $1.34 billion -5.5%N/A5.6 $136.23
12/30/202210,440,000 shares $1.37 billion +4.7%N/A5.7 $131.29
12/15/20229,970,000 shares $1.34 billion -8.8%N/A5.2 $134.24
11/30/202210,930,000 shares $1.49 billion +5.0%N/A5.5 $136.53
11/15/202210,410,000 shares $1.41 billion +6.9%N/A5.3 $135.11
10/31/20229,740,000 shares $1.25 billion -15.4%N/A5.1 $128.59
10/15/202211,510,000 shares $1.38 billion No ChangeN/A6.2 $119.58
9/30/20229,180,000 shares $1.07 billion +16.8%N/A4.9 $116.96
9/15/20227,860,000 shares $975.03 million +12.8%N/A4.1 $124.05
8/31/20226,970,000 shares $846.58 million -19.6%N/A3.5 $121.46
8/15/20228,670,000 shares $1.17 billion +14.4%N/A4.3 $134.82
7/31/20227,580,000 shares $940.53 million -2.3%N/A3.2 $124.08
7/15/20227,760,000 shares $956.42 million -12.7%N/A3 $123.25
6/30/20228,890,000 shares $1.05 billion +1.1%N/A3.3 $117.63
6/15/20228,790,000 shares $955.12 million +12.7%N/A3.2 $108.66
5/31/20227,800,000 shares $910.03 million -6.0%N/A2.9 $116.67
5/15/20228,300,000 shares $939.06 million +3.2%N/A3 $113.14
4/30/20228,040,000 shares $937.87 million -6.9%N/A3 $116.65
4/15/20228,640,000 shares $1.13 billion -9.5%N/A3.2 $130.86
3/31/20229,550,000 shares $1.24 billion -20.2%N/A3.5 $130.30
3/15/202211,970,000 shares $1.45 billion +6.2%N/A4.4 $121.13
2/28/202211,270,000 shares $1.42 billion +10.5%N/A4.1 $126.07
2/15/202210,200,000 shares $1.33 billion -4.5%N/A3.6 $129.98
1/31/202210,680,000 shares $1.41 billion +4.3%N/A4 $131.86
1/15/202210,240,000 shares $1.42 billion +9.6%N/A4.1 $138.95
12/31/20219,340,000 shares $1.43 billion -9.3%N/A4.3 $152.62
12/15/202110,300,000 shares $1.56 billion -1.4%N/A4.7 $151.90
11/30/202110,450,000 shares $1.61 billion -11.3%N/A5 $154.22
11/15/202111,780,000 shares $1.80 billion +6.9%N/A6 $153.18
10/29/202111,020,000 shares $1.76 billion -0.1%N/A5.2 $159.60
10/15/202111,030,000 shares $1.73 billion -14.6%N/A4.9 $157.06
9/30/202112,920,000 shares $2.09 billion +10.6%N/A5.1 $161.68
9/15/202111,680,000 shares $2.01 billion +1.9%N/A4.6 $171.80
8/31/202111,460,000 shares $1.97 billion +0.5%N/A4.3 $172.28
8/13/202111,400,000 shares $1.93 billion -12.6%N/A3.7 $169.40
7/30/202113,050,000 shares $2.16 billion -5.8%N/A4 $165.78
7/15/202113,860,000 shares $2.21 billion -4.6%N/A4.1 $159.25
6/30/202114,520,000 shares $2.38 billion -1.9%N/A4.3 $163.65
6/15/202114,800,000 shares $2.36 billion -0.9%N/A4.1 $159.44
5/28/202114,930,000 shares $2.27 billion -6.0%N/A4.1 $151.95
5/14/202115,880,000 shares $2.32 billion -16.8%N/A4.3 $146.13

IBB Short Interest - Frequently Asked Questions

Short interest is the volume of iShares Biotechnology ETF shares that have been sold short but have not yet been closed out or covered. As of April 30th, investors have sold 13,267,269 shares of IBB short. 28.20% of iShares Biotechnology ETF's shares are currently sold short. Learn More on iShares Biotechnology ETF's 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. IBB shares currently have a short interest ratio of 9.1. Learn More on iShares Biotechnology ETF's short interest ratio.

As of the most recent reporting period, the following institutional investors, funds, and major shareholders have reported short positions of iShares Biotechnology ETF: Caption Management LLC, Balyasny Asset Management L.P., J. Goldman & Co LP, Squarepoint Ops LLC, Sofinnova Investments Inc., Walleye Trading LLC, PEAK6 LLC, Volterra Technologies LP, Marshall Wace LLP, DLD Asset Management LP, and Jane Street Group LLC. These positions are disclosed in Form 13F filings with the Securities and Exchange Commission.

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. 28.20% of iShares Biotechnology ETF's floating shares are currently sold short.

iShares Biotechnology ETF saw a increase in short interest during the month of April. As of April 30th, there was short interest totaling 13,267,269 shares, an increase of 5.4% from the previous total of 12,584,040 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.

28.20% of iShares Biotechnology ETF's shares are currently sold short. Here is how the short interest of companies compare to iShares Biotechnology ETF: VanEck Pharmaceutical ETF (15.41%), VanEck Biotech ETF (0.38%), Invesco S&P SmallCap Health Care ETF (0.87%), Invesco Dorsey Wright Healthcare Momentum ETF (0.32%), ProShares Ultra Nasdaq Biotechnology (1.33%), Invesco Nasdaq Biotechnology ETF (1.17%), Global X HealthTech ETF (0.96%), Horizon Kinetics Medical ETF (0.63%), and ProShares UltraShort Nasdaq Biotechnology (8.13%).

As of the most recent reporting period, the following stocks had the largest short interest positions: SPDR S&P 500 ETF Trust ($86.09 billion), Invesco QQQ ($39.89 billion), iShares Russell 2000 ETF ($26.13 billion), Western Digital Corporation ($12.66 billion), Salesforce Inc. ($12.29 billion), Sandisk Corporation ($11.87 billion), SPDR S&P Biotech ETF ($9.82 billion), Lumentum Holdings Inc. ($8.51 billion), iShares 20+ Year Treasury Bond ETF ($7.76 billion), and Bloom Energy Corporation ($7.40 billion). View all of the most shorted stocks.

Short selling IBB is an investing strategy that aims to generate trading profit from iShares Biotechnology ETF as its price is falling. IBB shares are trading up $0.06 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.

A short squeeze for iShares Biotechnology ETF 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 IBB, 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 IBB, twice per month. The most recent reporting period available is April, 30 2026.

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

  • 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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This page (NASDAQ:IBB) was last updated on 5/11/2026 by MarketBeat.com Staff.
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