Masimo (MASI) Short Interest Ratio & Short Volume $151.82 -4.36 (-2.79%) As of 01:53 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 InterestSustainabilityTrendsBuy This Stock Masimo Short Interest DataMasimo (MASI) has a short interest of 2.58 million shares, representing 5.17% of the float (the number of shares available for trading by the public). This marks a -7.53% decrease in short interest from the previous month. The short interest ratio (days to cover) is 4.1, indicating that it would take 4.1 days of the average trading volume of 650,105 shares to cover all short positions.Current Short Interest2,580,000 sharesPrevious Short Interest2,790,000 sharesChange Vs. Previous Month-7.53%Dollar Volume Sold Short$415.28 millionShort Interest Ratio4.1 Days to CoverLast Record DateApril 30, 2025Outstanding Shares54,219,000 sharesFloat Size49,950,000 sharesShort Percent of Float5.17%Today's Trading Volume252,877 sharesAverage Trading Volume650,105 sharesToday's Volume Vs. Average39% Short Selling Masimo? Sign up to receive the latest short interest report for Masimo and its competitors with MarketBeat's FREE newsletter. Email Address Skip Charts & View Short Interest HistoryShort Interest ChartDays to Cover ChartShort Percent of Float ChartMASI Short Interest Over TimeMASI Days to Cover Over TimeMASI Percentage of Float Shorted Over Time Masimo Short Interest History Export to ExcelReport DateTotal Shares Sold ShortDollar Volume Sold ShortChange from Previous ReportPercentage of Float ShortedDays to CoverPrice on Report Date 4/30/20252,580,000 shares $415.28 million -7.5%5.2%4.1 $160.96 4/15/20252,790,000 shares $424.25 million -3.8%5.6%4.8 $152.06 3/31/20252,900,000 shares $483.14 million -13.4%5.8%4.9 $166.60 3/15/20253,350,000 shares $563.50 million -0.6%6.8%6.2 $168.21 2/28/20253,370,000 shares $636.15 million +12.0%6.8%6.5 $188.77 2/15/20253,010,000 shares $545.74 million +3.4%6.1%6 $181.31 1/31/20252,910,000 shares $507.01 million +3.2%5.9%5.6 $174.23 1/15/20252,820,000 shares $485.24 million +2.9%5.7%5.2 $172.07 12/31/20242,740,000 shares $452.92 million -20.6%5.6%4.9 $165.30 12/15/20243,450,000 shares $607.68 million +7.8%7.0%5.2 $176.14 Get the Latest News and Ratings for MASI and Related StocksEnter your email address below to receive the latest news and analysts' ratings for Masimo and its competitors with MarketBeat's FREE daily newsletter. 11/30/20243,200,000 shares $552.13 million -4.2%6.5%4.5 $172.54 11/15/20243,340,000 shares $537.97 million -0.3%6.8%4.7 $161.07 10/31/20243,350,000 shares $482.43 million -6.4%6.8%4.9 $144.01 10/15/20243,580,000 shares $515.27 million +3.2%7.3%4.7 $143.93 9/30/20243,470,000 shares $462.66 million +18.8%7.1%4.5 $133.33 9/15/20242,920,000 shares $329.38 million -25.7%5.9%4.2 $112.80 8/31/20243,930,000 shares $461.85 million -41.8%8.0%5.9 $117.52 8/15/20246,750,000 shares $820.60 million +43.3%13.7%9.1 $121.57 7/31/20244,710,000 shares $503.88 million +82.6%9.6%5.6 $106.98 7/15/20242,580,000 shares $280.91 million -3.4%5.3%3.6 $108.88 6/30/20242,670,000 shares $336.26 million -58.9%5.4%4 $125.94 6/15/20246,500,000 shares $881.99 million +33.2%13.2%9.6 $135.69 5/31/20244,880,000 shares $607.56 million +58.4%10.0%7.6 $124.50 5/15/20243,080,000 shares $357.74 million -20.8%6.3%5 $116.15 4/30/20243,890,000 shares $522.85 million -3.7%8.0%7.1 $134.41 4/15/20244,040,000 shares $557.96 million -4.5%8.3%7.7 $138.11 3/31/20244,230,000 shares $621.18 million -9.0%8.7%7 $146.85 3/15/20244,650,000 shares $616.96 million -2.1%9.5%7.4 $132.68 2/29/20244,750,000 shares $610.57 million -7.1%9.7%7 $128.54 2/15/20245,110,000 shares $685.46 million +3.4%10.5%7.1 $134.14 1/31/20244,940,000 shares $636.96 million +8.3%10.0%6 $128.94 1/15/20244,560,000 shares $539.54 million +4.1%9.3%5 $118.32 12/31/20234,380,000 shares $513.38 million -1.6%8.9%4.8 $117.21 12/15/20234,450,000 shares $497.02 million -1.1%9.0%4.5 $111.69 11/30/20234,500,000 shares $421.92 million +8.4%9.1%4.4 $93.76 11/15/20234,150,000 shares $378.27 million +7.0%8.4%4.1 $91.15 10/31/20233,880,000 shares $314.78 million -2.8%7.9%3.9 $81.13 10/15/20233,990,000 shares $308.63 million No Change8.1%4.1 $77.35 9/30/20233,990,000 shares $349.84 million +2.1%8.1%3.7 $87.68 9/15/20233,910,000 shares $395.38 million +11.4%7.9%3.9 $101.12The Trump Dump is starting; Get out of stocks now? (Ad)The first 365 days of the Trump presidency… Will be the best time to get rich in American history.If I’m right about this (like I was before) a modest $900 investment could grow to a life-changing a 8/31/20233,510,000 shares $401.12 million -4.6%7.1%4 $114.28 8/15/20233,680,000 shares $407.71 million +6.7%7.5%4.5 $110.79 7/31/20233,450,000 shares $421.94 million +34.8%7.0%4.4 $122.30 7/15/20232,560,000 shares $382.90 million +0.4%5.2%3.9 $149.57 6/30/20232,550,000 shares $419.60 million +2.4%5.2%5.8 $164.55 6/15/20232,490,000 shares $406.54 million +32.5%5.1%6.1 $163.27 5/31/20231,880,000 shares $304.26 million +75.7%3.8%4.8 $161.84 5/15/20231,070,000 shares $185.43 million +23.6%2.2%2.9 $173.30 4/30/2023865,600 shares $163.72 million +1.3%1.8%2.8 $189.14 4/15/2023854,700 shares $163.82 million +16.4%1.8%2.8 $191.67 3/31/2023734,200 shares $135.49 million -17.9%1.5%2.2 $184.54 3/15/2023894,000 shares $154.79 million +0.7%1.9%2.5 $173.14 2/28/2023887,500 shares $148.49 million -6.6%1.8%2.2 $167.31 2/15/2023950,500 shares $159.54 million -15.9%2.0%2.3 $167.85 1/31/20231,130,000 shares $192.19 million -22.6%2.3%2.2 $170.08 1/15/20231,460,000 shares $228.86 million -5.2%3.0%2.5 $156.75 12/30/20221,540,000 shares $227.84 million -21.0%3.2%2.5 $147.95 12/15/20221,950,000 shares $281.40 million -13.0%4.0%3 $144.31 11/30/20222,240,000 shares $324.67 million -14.8%4.6%3.2 $144.94 11/15/20222,630,000 shares $332.91 million -9.6%5.4%3.5 $126.58 10/31/20222,910,000 shares $382.96 million -5.5%6.0%3.3 $131.60 10/15/20223,080,000 shares $407.58 million -10.2%6.4%3.3 $132.33 9/30/20223,430,000 shares $484.18 million +4.3%7.1%3.7 $141.16 9/15/20223,290,000 shares $510.77 million -4.6%6.8%3.6 $155.25 8/31/20223,450,000 shares $506.77 million -15.9%7.2%3.9 $146.89 8/15/20224,100,000 shares $655.06 million +16.2%8.5%4.7 $159.77 7/31/20223,530,000 shares $510.37 million +22.2%7.2%4.1 $144.58 7/15/20222,890,000 shares $369.49 million +7.0%5.9%3.3 $127.85 6/30/20222,700,000 shares $352.81 million -2.9%5.5%3.2 $130.67 6/15/20222,780,000 shares $351.75 million -18.0%5.7%2.9 $126.53 5/31/20223,390,000 shares $476.06 million +1.5%6.6%3.4 $140.43 5/15/20223,340,000 shares $454.37 million +44.0%6.5%3.1 $136.04 4/30/20222,320,000 shares $262.09 million +5.5%4.5%2.1 $112.97 4/15/20222,200,000 shares $296.71 million +46.7%4.3%2.2 $134.87 3/31/20221,500,000 shares $218.31 million +63.8%2.9%1.6 $145.54 3/15/2022915,800 shares $127.06 million +25.8%1.8%1.1 $138.74 2/28/2022728,100 shares $114.64 million -45.7%1.4%1 $157.45 2/15/20221,340,000 shares $306.65 million +1.5%2.6%2.3 $228.84 1/31/20221,320,000 shares $290.23 million -15.4%2.6%4.2 $219.87 1/15/20221,560,000 shares $363.60 million +16.4%3.1%5.6 $233.08 12/31/20211,340,000 shares $392.33 million -9.5%2.6%5.4 $292.78 12/15/20211,480,000 shares $420.13 million -6.3%2.9%6 $283.87 11/30/20211,580,000 shares $439.43 million -2.5%3.1%6.6 $278.12 11/15/20211,620,000 shares $484.02 million +10.2%3.2%6.7 $298.78 10/29/20211,470,000 shares $416.80 million -7.0%2.9%6.4 $283.54 10/15/20211,580,000 shares $452.07 million -1.9%3.1%7 $286.12 9/30/20211,610,000 shares $435.84 million +12.6%3.2%6.9 $270.71 9/15/20211,430,000 shares $390.02 million -8.9%2.8%5.6 $272.74 8/31/20211,570,000 shares $426.32 million -4.3%3.1%5.6 $271.54 8/13/20211,640,000 shares $433.32 million No Change3.2%5.4 $264.22The Trump Dump is starting; Get out of stocks now? (Ad)The first 365 days of the Trump presidency… Will be the best time to get rich in American history.If I’m right about this (like I was before) a modest $900 investment could grow to a life-changing a 7/30/20211,640,000 shares $446.72 million +9.3%3.2%5 $272.39 7/15/20211,500,000 shares $399 million +11.1%3.0%4.2 $266.00 6/30/20211,350,000 shares $327.31 million +8.0%2.7%3.9 $242.45 6/15/20211,250,000 shares $280.74 million -3.1%2.5%3.7 $224.59 5/28/20211,290,000 shares $278.12 million +5.7%2.6%3.8 $215.60 5/14/20211,220,000 shares $267.33 million +31.4%2.4%3.6 $219.12 4/30/2021928,800 shares $216.80 million +19.4%1.8%2.7 $233.42 4/15/2021778,000 shares $186.37 million -12.0%1.5%2.4 $239.55 3/31/2021884,000 shares $199.90 million -8.6%1.7%2.6 $226.13 3/15/2021966,700 shares $222.73 million -0.3%1.9%2.9 $230.40 2/26/2021969,600 shares $238.63 million +9.8%1.9%3.1 $246.11 2/12/2021883,100 shares $239.13 million -0.7%1.7%2.8 $270.79 1/29/2021889,700 shares $229.16 million -13.6%1.8%2.7 $257.57 1/15/20211,030,000 shares $269.61 million -3.7%2.0%3.2 $261.76 12/31/20201,070,000 shares $286.25 million -2.7%2.1%3.4 $267.52 12/15/20201,100,000 shares $289.30 million -14.1%2.2%3.2 $263.00 11/30/20201,280,000 shares $325.64 million +7.6%2.5%3.5 $254.41 11/15/20201,190,000 shares $292.19 million -4.0%2.3%3.3 $245.54 10/30/20201,240,000 shares $279.84 million -6.8%2.4%3.4 $225.68 10/15/20201,330,000 shares $308.41 million -2.2%2.6%3.4 $231.89 9/30/20201,360,000 shares $321.04 million +10.6%2.7%3.2 $236.06 9/15/20201,230,000 shares $274.77 million -0.8%2.4%2.8 $223.39 8/31/20201,240,000 shares $277.76 million -1.6%2.4%2.6 $224.00 8/14/20201,260,000 shares $269.75 million +6.8%2.5%2.2 $214.09 7/31/20201,180,000 shares $259.74 million +27.5%2.3%1.9 $220.12 7/15/2020925,800 shares $207.70 million -31.4%1.9%1.4 $224.35 6/30/20201,350,000 shares $307.79 million -20.6%2.7%2 $227.99 6/15/20201,700,000 shares $381.12 million +12.6%3.4%2.5 $224.19 5/29/20201,510,000 shares $353.88 million +19.8%3.0%2.1 $234.36 MASI Short Interest - Frequently Asked Questions What is Masimo's current short interest? Short interest is the volume of Masimo shares that have been sold short but have not yet been covered or closed out. As of April 30th, traders have sold 2,580,000 shares of MASI short. 5.17% of Masimo's shares are currently sold short. Learn More on Masimo's current short interest. What is a good short interest ratio for Masimo? 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. MASI shares currently have a short interest ratio of 4.0. Learn More on Masimo's short interest ratio. Which institutional investors are shorting Masimo? As of the most recent reporting period, the following institutional investors, funds, and major shareholders have reported short positions of Masimo: Millennium Management LLC, PEAK6 LLC, Walleye Capital LLC, and Simplex Trading LLC. These positions are disclosed in Form 13F filings with the Securities and Exchange Commission. What is a good short interest percentage for Masimo? 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. 5.17% of Masimo's floating shares are currently sold short. Is Masimo's short interest increasing or decreasing? Masimo saw a decline in short interest in April. As of April 30th, there was short interest totaling 2,580,000 shares, a decline of 7.5% from the previous total of 2,790,000 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 Masimo's float size? Masimo currently has issued a total of 54,219,000 shares. Some of Masimo's 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. Masimo currently has a public float of 49,950,000 shares. How does Masimo's short interest compare to its competitors? 5.17% of Masimo's shares are currently sold short. Here is how the short interest of companies in the sector of "medical" compare to Masimo: DexCom, Inc. (2.91%), STERIS plc (1.37%), Insulet Co. (3.15%), Baxter International Inc. (3.40%), Hologic, Inc. (2.42%), Globus Medical, Inc. (3.07%), Teleflex Incorporated (2.48%), Integer Holdings Co. (9.52%), Alphatec Holdings, Inc. (9.05%), AtriCure, Inc. (3.09%), Which stocks are the most shorted right now? As of the most recent reporting period, the following stocks had the largest short interest positions: Spotify Technology S.A. ($4.67 billion), Charter Communications, Inc. ($4.58 billion), Capital One Financial Co. ($4.47 billion), The Kroger Co. ($2.56 billion), Reddit, Inc. ($2.23 billion), Rivian Automotive, Inc. ($2.16 billion), Live Nation Entertainment, Inc. ($1.90 billion), SoFi Technologies, Inc. ($1.85 billion), Zscaler, Inc. ($1.75 billion), and Omnicom Group Inc. ($1.75 billion). View all of the most shorted stocks. What does it mean to sell short Masimo stock? Short selling MASI is an investing strategy that aims to generate trading profit from Masimo as its price is falling. MASI shares are trading up $1.04 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 Masimo? A short squeeze for Masimo 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 MASI, which in turn drives the price of the stock up even further. How often is Masimo'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 MASI, twice per month. The most recent reporting period available is April, 30 2025. More Short Interest Resources from MarketBeat Related Companies DXCM Short Squeeze STE Short Squeeze PODD Short Squeeze BAX Short Squeeze HOLX Short Squeeze GMED Short Squeeze TFX Short Squeeze ITGR Short Squeeze ATEC Short Squeeze ATRC 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:MASI) was last updated on 5/21/2025 by MarketBeat.com Staff From Our PartnersMarket Panic: Trump Just Dropped a Bomb on Your Stockstock Market Panic: Trump Just Dropped a Bomb on Your Stocks The market is in freefall—and Trump's new tarif...American Alternative | SponsoredGold Hits New Highs as Global Markets SpiralWhen Trump took office in 2017, gold was just $1,100 an ounce. 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