Pacific Biosciences of California (PACB) Short Interest Ratio & Short Volume $1.28 +0.05 (+3.63%) As of 03:55 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 InterestTrendsBuy This Stock Pacific Biosciences of California Short Interest DataPacific Biosciences of California (PACB) has a short interest of 39.64 million shares, representing 13.55% of the float (the number of shares available for trading by the public). This marks a -23.80% decrease in short interest from the previous month. The short interest ratio (days to cover) is 4.5, indicating that it would take 4.5 days of the average trading volume of 9.78 million shares to cover all short positions.Current Short Interest39,640,000 sharesPrevious Short Interest52,020,000 sharesChange Vs. Previous Month-23.80%Dollar Volume Sold Short$47.57 millionShort Interest Ratio4.5 Days to CoverLast Record DateJune 15, 2025Outstanding Shares300,080,000 sharesShort Percent of Float13.55%Today's Trading Volume15,920,484 sharesAverage Trading Volume9,776,617 sharesToday's Volume Vs. Average163% Short Selling Pacific Biosciences of California? Sign up to receive the latest short interest report for Pacific Biosciences of California and its competitors with MarketBeat's FREE newsletter. Email Address Skip Charts & View Short Interest HistoryShort Interest ChartDays to Cover ChartShort Percent of Float ChartPACB Short Interest Over TimePACB Days to Cover Over TimePACB Percentage of Float Shorted Over Time Pacific Biosciences of California Short Interest History Export to ExcelReport DateTotal Shares Sold ShortDollar Volume Sold ShortChange from Previous ReportPercentage of Float ShortedDays to CoverPrice on Report Date 6/15/202539,640,000 shares $47.57 million -23.8%13.5%4.5 $1.20 5/31/202552,020,000 shares $51.37 million -8.7%19.5%6 $0.99 5/15/202556,950,000 shares $60.37 million +15.7%21.3%6.5 $1.06 4/30/202549,210,000 shares $54.62 million +4.3%N/A4.8 $1.11 4/15/202547,200,000 shares $59.94 million -13.6%17.7%4.4 $1.27 3/31/202554,600,000 shares $64.43 million +2.2%20.4%4.7 $1.18 3/15/202553,410,000 shares $65.16 million -13.8%20.0%4.9 $1.22 2/28/202561,980,000 shares $89.87 million -7.1%23.2%5.5 $1.45 2/15/202566,690,000 shares $123.38 million +10.4%25.0%6.1 $1.85 1/31/202560,400,000 shares $93.02 million -0.2%N/A5.7 $1.54 Get the Latest News and Ratings for PACB and Related StocksEnter your email address below to receive the latest news and analysts' ratings for Pacific Biosciences of California and its competitors with MarketBeat's FREE daily newsletter. 1/15/202560,540,000 shares $105.64 million +6.5%N/A6 $1.75 12/31/202456,850,000 shares $104.04 million +7.1%N/A5.8 $1.83 12/15/202453,060,000 shares $104.00 million -2.4%N/A5.7 $1.96 11/30/202454,380,000 shares $103.87 million +4.3%N/A5.6 $1.91 11/15/202452,140,000 shares $83.16 million +3.4%N/A5.5 $1.60 10/31/202450,410,000 shares $109.39 million +3.9%N/A5.8 $2.17 10/15/202448,540,000 shares $101.93 million -6.0%N/A5.9 $2.10 9/30/202451,640,000 shares $87.79 million +11.0%N/A5.7 $1.70 9/15/202446,530,000 shares $84.22 million -23.8%N/A4.9 $1.81 8/31/202461,030,000 shares $83.61 million +1.8%N/A6.8 $1.37 8/15/202459,960,000 shares $101.33 million +5.0%N/A6.8 $1.69 7/31/202457,100,000 shares $117.63 million -7.4%N/A5.9 $2.06 7/15/202461,680,000 shares $99.92 million +9.2%N/A6.2 $1.62 6/30/202456,470,000 shares $77.36 million +3.5%N/A5.3 $1.37 6/15/202454,570,000 shares $96.04 million +0.6%N/A5.3 $1.76 5/31/202454,250,000 shares $97.11 million -4.1%N/A5.2 $1.79 5/15/202456,580,000 shares $121.36 million +7.1%N/A5.2 $2.15 4/30/202452,820,000 shares $87.15 million +8.9%N/A5.1 $1.65 4/15/202448,520,000 shares $137.55 million -1.1%N/A5 $2.84 3/31/202449,050,000 shares $183.94 million +7.6%N/A5.6 $3.75 3/15/202445,570,000 shares $172.71 million +4.7%N/A5.4 $3.79 2/29/202443,540,000 shares $240.78 million +7.8%N/A5.3 $5.53 2/15/202440,380,000 shares $269.33 million +18.1%N/A5.4 $6.67 1/31/202434,190,000 shares $222.58 million -5.0%N/A5.1 $6.51 1/15/202436,000,000 shares $241.56 million -4.7%N/A5.6 $6.71 12/31/202337,780,000 shares $370.62 million +8.3%N/A6.7 $9.81 12/15/202334,890,000 shares $329.36 million +4.4%N/A6.7 $9.44 11/30/202333,430,000 shares $283.49 million -14.8%N/A7 $8.48 11/15/202339,230,000 shares $306.39 million +11.7%N/A8.5 $7.81 10/31/202335,120,000 shares $217.04 million -6.9%N/A8.1 $6.18Trump set to Boost Social Security Checks by 400%? (Ad)If you collect—or plan to collect—Social Security, you need to see this. A new initiative tied to President Trump's Executive Order #14196 could not only save Social Security from collapse... ...but potentially increase benefits by up to 400%, according to legendary investor Louis Navellier.Click here to watch the full presentation before it's too late. 10/15/202337,740,000 shares $301.17 million +14.1%N/A9.6 $7.98 9/30/202333,070,000 shares $276.13 million -2.2%N/A8.6 $8.35 9/15/202333,820,000 shares $352.40 million +2.3%N/A9.4 $10.42 8/31/202333,060,000 shares $372.92 million +5.3%N/A9.3 $11.28 8/15/202331,390,000 shares $352.20 million +10.6%N/A8.3 $11.22 7/31/202328,390,000 shares $375.03 million -7.6%N/A7.7 $13.21 7/15/202330,710,000 shares $421.96 million -2.7%N/A8.6 $13.74 6/30/202331,550,000 shares $419.62 million +25.3%N/A8.8 $13.30 6/15/202325,190,000 shares $335.28 million -1.0%N/A6.7 $13.31 5/31/202325,440,000 shares $314.95 million +5.2%N/A6.7 $12.38 5/15/202324,180,000 shares $300.80 million -5.0%N/A6.6 $12.44 4/30/202325,440,000 shares $269.66 million -6.4%N/A6.7 $10.60 4/15/202327,180,000 shares $304.42 million +8.3%N/A6.6 $11.20 3/31/202325,100,000 shares $290.66 million -4.5%N/A5.8 $11.58 3/15/202326,280,000 shares $238.10 million +14.2%N/A6.2 $9.06 2/28/202323,020,000 shares $209.02 million +8.4%N/A5.6 $9.08 2/15/202321,240,000 shares $235.55 million -5.6%N/A5.3 $11.09 1/31/202322,490,000 shares $249.41 million -7.1%N/A5 $11.09 1/15/202324,200,000 shares $265.23 million -1.9%N/A4.9 $10.96 12/30/202224,670,000 shares $201.80 million +8.1%N/A5.1 $8.18 12/15/202222,820,000 shares $206.75 million +3.8%N/A4.4 $9.06 11/30/202221,990,000 shares $236.39 million -9.1%N/A3.9 $10.75 11/15/202224,190,000 shares $270.93 million +4.1%N/A4 $11.20 10/31/202223,240,000 shares $196.15 million -3.0%N/A3 $8.44 10/15/202223,950,000 shares $146.10 million -5.3%N/A3.1 $6.10 9/30/202225,290,000 shares $146.81 million -16.6%N/A3.3 $5.81 9/15/202230,310,000 shares $200.35 million +4.8%N/A3.8 $6.61 8/31/202228,930,000 shares $169.53 million -11.6%N/A3.6 $5.86 8/15/202232,720,000 shares $273.54 million -7.5%N/A3.9 $8.36 7/31/202235,360,000 shares $154.52 million -1.9%N/A5.1 $4.37 7/15/202236,030,000 shares $152.77 million -12.2%N/A5.1 $4.24 6/30/202241,020,000 shares $181.31 million +7.9%N/A5.7 $4.42 6/15/202238,010,000 shares $162.68 million +10.6%N/A5.3 $4.28 5/31/202234,370,000 shares $193.50 million +3.0%N/A5 $5.63 5/15/202233,370,000 shares $194.88 million +1.2%N/A5.2 $5.84 4/30/202232,960,000 shares $208.97 million +8.8%N/A5.5 $6.34 4/15/202230,290,000 shares $228.39 million -2.8%N/A5.2 $7.54 3/31/202231,170,000 shares $283.65 million +1.3%N/A5.6 $9.10 3/15/202230,760,000 shares $281.76 million +3.5%N/A6.3 $9.16 2/28/202229,710,000 shares $354.14 million +8.5%N/A6.6 $11.92 2/15/202227,390,000 shares $311.70 million +3.1%N/A6.3 $11.38 1/31/202226,580,000 shares $297.16 million +22.9%N/A7.1 $11.18 1/15/202221,630,000 shares $268.86 million +8.6%N/A6.9 $12.43 12/31/202119,910,000 shares $407.36 million -1.6%N/A7.8 $20.46 12/15/202120,230,000 shares $444.86 million +19.2%N/A9 $21.99 11/30/202116,970,000 shares $393.87 million -5.1%N/A8.5 $23.21 11/15/202117,890,000 shares $477.66 million +0.9%N/A9.6 $26.70 10/29/202117,730,000 shares $469.49 million +14.2%9.3%9.9 $26.48 10/15/202115,520,000 shares $378.53 million +9.3%8.2%8.5 $24.39 9/30/202114,200,000 shares $362.81 million +9.3%7.5%7.4 $25.55Trump set to Boost Social Security Checks by 400%? (Ad)If you collect—or plan to collect—Social Security, you need to see this. A new initiative tied to President Trump's Executive Order #14196 could not only save Social Security from collapse... ...but potentially increase benefits by up to 400%, according to legendary investor Louis Navellier.Click here to watch the full presentation before it's too late. 9/15/202112,990,000 shares $359.04 million +2.4%6.8%6.6 $27.64 8/31/202112,690,000 shares $397.32 million +8.8%6.7%6.4 $31.31 8/13/202111,660,000 shares $343.62 million -2.1%6.1%5.7 $29.47 7/30/202111,910,000 shares $382.91 million -2.6%6.3%5.2 $32.15 7/15/202112,230,000 shares $330.21 million -10.5%6.5%5 $27.00 6/30/202113,660,000 shares $477.69 million -0.8%7.2%5.5 $34.97 6/15/202113,770,000 shares $385.84 million +0.8%7.3%5.2 $28.02 5/28/202113,660,000 shares $369.50 million -2.6%7.2%4.7 $27.05 5/14/202114,030,000 shares $312.87 million +3.1%N/A3.9 $22.30 4/30/202113,610,000 shares $455.66 million +15.9%N/A3.2 $33.48 4/15/202111,740,000 shares $382.14 million -8.9%N/A2.8 $32.55 3/31/202112,890,000 shares $386.06 million +12.4%N/A2.7 $29.95 3/15/202111,470,000 shares $388.72 million +28.9%N/A2.1 $33.89 2/26/20218,900,000 shares $277.46 million -8.3%N/A1.6 $31.18 2/12/20219,710,000 shares $496.67 million -25.3%N/A1.9 $51.15 1/29/202113,000,000 shares $445.64 million -1.2%N/A2.7 $34.28 1/15/202113,160,000 shares $496.40 million -15.7%N/A2.7 $37.72 12/31/202015,610,000 shares $411.32 million +30.7%N/A3.2 $26.35 12/15/202011,940,000 shares $249.55 million -12.8%N/A2.6 $20.90 11/30/202013,690,000 shares $211.24 million -5.1%N/A3.1 $15.43 11/15/202014,430,000 shares $241.56 million -3.7%N/A3.4 $16.74 10/30/202014,990,000 shares $200.27 million -14.0%N/A3.5 $13.36 10/15/202017,420,000 shares $243.18 million +0.2%N/A4.5 $13.96 9/30/202017,380,000 shares $171.54 million +0.9%N/A5.3 $9.87 9/15/202017,230,000 shares $126.12 million +3.8%N/A7 $7.32 8/31/202016,600,000 shares $109.56 million -4.8%N/A8.3 $6.60 8/14/202017,430,000 shares $100.22 million +0.1%12.3%9.9 $5.75 7/31/202017,410,000 shares $64.94 million -2.4%12.3%13.7 $3.73 7/15/202017,830,000 shares $74.35 million -0.1%12.6%14.2 $4.17 PACB Short Interest - Frequently Asked Questions What is Pacific Biosciences of California's current short interest? Short interest is the volume of Pacific Biosciences of California shares that have been sold short but have not yet been closed out or covered. As of June 15th, investors have sold 39,640,000 shares of PACB short. 13.55% of Pacific Biosciences of California's shares are currently sold short. Learn More on Pacific Biosciences of California's current short interest. What is a good short interest ratio for Pacific Biosciences of California? 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. PACB shares currently have a short interest ratio of 4.0. Learn More on Pacific Biosciences of California's short interest ratio. Which institutional investors are shorting Pacific Biosciences of California? As of the most recent reporting period, the following institutional investors, funds, and major shareholders have reported short positions of Pacific Biosciences of California: Walleye Trading LLC, Simplex Trading LLC, and National Bank of Canada FI. These positions are disclosed in Form 13F filings with the Securities and Exchange Commission. What is a good short interest percentage for Pacific Biosciences of California? 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. 13.55% of Pacific Biosciences of California's floating shares are currently sold short. Is Pacific Biosciences of California's short interest increasing or decreasing? Pacific Biosciences of California saw a decrease in short interest in the month of June. As of June 15th, there was short interest totaling 39,640,000 shares, a decrease of 23.8% from the previous total of 52,020,000 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 Pacific Biosciences of California's short interest compare to its competitors? 13.55% of Pacific Biosciences of California's shares are currently sold short. Here is how the short interest of companies compare to Pacific Biosciences of California: Harvard Bioscience, Inc. (7.56%), Thermo Fisher Scientific Inc. (1.30%), Agilent Technologies, Inc. (1.45%), Mettler-Toledo International, Inc. (3.01%), Waters Corporation (2.90%), Illumina, Inc. (4.09%), Bio-Techne Corp (4.08%), Charles River Laboratories International, Inc. (5.38%), Bio-Rad Laboratories, Inc. (4.83%), Bruker Corporation (9.59%), 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 ($69.26 billion), Invesco QQQ ($25.22 billion), iShares Russell 2000 ETF ($20.33 billion), iShares 20+ Year Treasury Bond ETF ($9.99 billion), MicroStrategy Incorporated ($9.12 billion), Canadian Natural Resources Limited ($6.73 billion), SPDR S&P Biotech ETF ($6.52 billion), Invesco S&P 500 Equal Weight ETF ($5.60 billion), Financial Select Sector SPDR Fund ($4.64 billion), and iShares iBoxx $ Investment Grade Corporate Bond ETF ($4.59 billion). View all of the most shorted stocks. What does it mean to sell short Pacific Biosciences of California stock? Short selling PACB is an investing strategy that aims to generate trading profit from Pacific Biosciences of California as its price is falling. PACB shares are trading down $0.05 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 Pacific Biosciences of California? A short squeeze for Pacific Biosciences of California 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 PACB, which in turn drives the price of the stock up even further. How often is Pacific Biosciences of California's 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 PACB, twice per month. The most recent reporting period available is June, 15 2025. More Short Interest Resources from MarketBeat Related Companies Harvard Bioscience Short Squeeze Thermo Fisher Scientific Short Squeeze Agilent Technologies Short Squeeze Mettler-Toledo International Short Squeeze Waters Short Squeeze Illumina Short Squeeze Bio-Techne Short Squeeze Charles River Laboratories International Short Squeeze Bio-Rad Laboratories Short Squeeze Bruker Short Squeeze Short Interest Tools Stocks to Short Largest Short Interest Positions Short Interest Increases Short Interest Decreases Short Interest Reporting Dates This page (NASDAQ:PACB) was last updated on 7/1/2025 by MarketBeat.com Staff From Our PartnersThis Crypto Is Set to Explode in JanuaryFree summit: How to profit from the Coinbase-Deribit deal Our hedge fund experts know exactly what this mea...Crypto 101 Media | SponsoredTrump set to Boost Social Security Checks by 400%?If you collect—or plan to collect—Social Security, you need to see this. A new initiative tied to President...InvestorPlace | Sponsored3..2..1.. AI 2.0 ignition (don’t sleep on this)I just put together an urgent new presentation that you need to see right away. In short: I believe we are...Timothy Sykes | SponsoredThe $7 company helping Nvidia build the world’s first trillion-dollar robot …Michael Robinson has been at the forefront of the technology market for over 40 years. Spotting some profit...Weiss Ratings | 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 | SponsoredGold prediction: $5,000/oz. or higher is comingThe perfect gold play right now? (currently under $10) Everything in the news now lines up perfectly for an...Stansberry Research | SponsoredElon’s BIGGEST warning yet?Tesla's About to Prove Everyone Wrong... Again Back in 2018, when Jeff Brown told everyone to buy Tesla… ...Brownstone Research | SponsoredTrump wipes out trillions overnight…Is there anybody more powerful than Donald Trump right now? In a single tariff announcement, he wiped out n...Porter & Company | 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 Pacific Biosciences of California, Inc. Please log in to your account or sign up in order to add this asset to your watchlist. Share Pacific Biosciences of California 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.
