This company has been marked as potentially delisted and may not be actively trading. Rubius Therapeutics (RUBY) Short Interest Ratio & Short Volume Add Compare Share Share Short Interest Stock AnalysisBuy This Stock Rubius Therapeutics Short Interest DataRubius Therapeutics (RUBY) has a short interest of 2.80 million shares, representing 6.10% of the float (the number of shares available for trading by the public). This marks a 83.01% increase in short interest from the previous month. The short interest ratio (days to cover) is 0.7, indicating that it would take 0.7 days of the average trading volume of 1.15 million shares to cover all short positions.Current Short Interest2,800,000 sharesPrevious Short Interest1,530,000 sharesChange Vs. Previous Month+83.01%Dollar Volume Sold Short$408.52 thousandShort Interest Ratio0.7 Days to CoverLast Record DateFebruary 28, 2023Outstanding Shares90,480,000 sharesFloat Size45,880,000 sharesShort Percent of Float6.10%Today's Trading Volume755,858 sharesAverage Trading Volume1,154,788 sharesToday's Volume Vs. Average65% Short Selling Rubius Therapeutics? Sign up to receive the latest short interest report for Rubius Therapeutics and its competitors with MarketBeat's FREE newsletter. Email Address Skip Charts & View Short Interest HistoryShort Interest ChartDays to Cover ChartShort Percent of Float ChartRUBY Short Interest Over TimeRUBY Days to Cover Over TimeRUBY Percentage of Float Shorted Over Time Rubius Therapeutics Short Interest History Export to ExcelReport DateTotal Shares Sold ShortDollar Volume Sold ShortChange from Previous ReportPercentage of Float ShortedDays to CoverPrice on Report Date 2/28/20232,800,000 shares $408.52 thousand +83.0%6.1%0.7 $0.15 2/15/20231,530,000 shares $257.04 thousand -18.2%3.3%0.6 $0.17 1/31/20231,870,000 shares $487.14 thousand -24.6%4.1%1.4 $0.26 1/15/20232,480,000 shares $730.86 thousand +21.6%5.5%2 $0.29 12/30/20222,040,000 shares $357 thousand +13.3%4.5%1.8 $0.18 12/15/20221,800,000 shares $324.18 thousand +5.9%4.0%2.4 $0.18 11/30/20221,700,000 shares $377.40 thousand -9.1%3.7%1 $0.22 11/15/20221,870,000 shares $527.71 thousand -14.2%4.1%0.5 $0.28 10/31/20222,180,000 shares $739.02 thousand -18.4%4.8%0.6 $0.34 10/15/20222,670,000 shares $1.05 million -10.7%5.9%0.8 $0.40 Get the Latest News and Ratings for RUBY and Related StocksEnter your email address below to receive the latest news and analysts' ratings for Rubius Therapeutics and its competitors with MarketBeat's FREE daily newsletter. 9/30/20222,990,000 shares $1.30 million +19.1%6.6%0.9 $0.43 9/15/20222,510,000 shares $1.74 million +4.2%5.5%0.7 $0.69 8/31/20222,410,000 shares $1.69 million -31.5%5.3%0.9 $0.70 8/15/20223,520,000 shares $2.85 million -6.6%7.7%5 $0.81 7/31/20223,770,000 shares $2.65 million -2.1%8.3%4.7 $0.70 7/15/20223,850,000 shares $3.21 million -2.8%8.5%3.6 $0.84 6/30/20223,960,000 shares $3.37 million -28.0%8.7%2.6 $0.85 6/15/20225,500,000 shares $4.62 million -8.5%12.1%3.5 $0.84 5/31/20226,010,000 shares $6.61 million -5.2%13.2%3.7 $1.10 5/15/20226,340,000 shares $8.24 million -9.4%13.9%4.2 $1.30 4/30/20227,000,000 shares $11.62 million -4.2%15.4%4.9 $1.66 4/15/20227,310,000 shares $14.55 million -20.6%16.2%5.2 $1.99 3/31/20229,210,000 shares $50.75 million -6.0%20.4%10.3 $5.51 3/15/20229,800,000 shares $53.61 million -10.7%21.7%13.8 $5.47 2/28/202210,970,000 shares $54.74 million +3.6%24.3%18.2 $4.99 2/15/202210,590,000 shares $61.00 million +12.9%23.5%18.7 $5.76 1/31/20229,380,000 shares $63.32 million +14.4%20.7%18.1 $6.75 1/15/20228,200,000 shares $72.32 million -10.7%18.1%18.1 $8.82 12/31/20219,180,000 shares $88.86 million +4.2%N/A23.3 $9.68 12/15/20218,810,000 shares $116.38 million +20.0%19.4%23 $13.21 11/30/20217,340,000 shares $90.72 million -5.1%16.2%23 $12.36 11/15/20217,730,000 shares $104.20 million +7.1%17.1%25.6 $13.48 10/29/20217,220,000 shares $102.60 million -0.8%16.0%22.9 $14.21 10/15/20217,280,000 shares $118.52 million -1.8%16.1%24.2 $16.28 9/30/20217,410,000 shares $132.49 million +0.7%16.4%23.7 $17.88 9/15/20217,360,000 shares $147.20 million +1.1%16.3%20.4 $20.00 8/31/20217,280,000 shares $158.12 million +9.2%16.1%17.2 $21.72 8/13/20216,670,000 shares $163.42 million No Change14.8%14.3 $24.50 7/30/20216,670,000 shares $143.34 million +3.3%14.9%13.6 $21.49 7/15/20216,460,000 shares $147.87 million -2.4%14.4%12.2 $22.89Trump’s national nightmare is here (Ad)Porter Stansberry and Jeff Brown say a new U.S. national emergency is already underway — and it could trigger the biggest forced rotation of capital since World War II. They reveal why Trump is mobilizing America’s tech giants… and name the two stocks most likely to soar as trillions shift behind the scenes.Watch the National Emergency broadcast here 6/30/20216,620,000 shares $161.59 million +34.3%14.8%11.5 $24.41 6/15/20214,930,000 shares $125.96 million +1.0%11.7%7 $25.55 5/28/20214,880,000 shares $119.22 million +6.8%11.6%3 $24.43 5/14/20214,570,000 shares $107.62 million -1.9%11.0%2.5 $23.55 4/30/20214,660,000 shares $116.73 million +1.5%11.4%2.6 $25.05 4/15/20214,590,000 shares $109.38 million -28.2%11.2%2.5 $23.83 3/31/20216,390,000 shares $161.73 million -32.7%17.9%3.5 $25.31 3/15/20219,490,000 shares $155.92 million +26.5%26.4%5.6 $16.43 2/26/20217,500,000 shares $60.15 million +1.2%22.8%5.1 $8.02 2/12/20217,410,000 shares $99.52 million -2.8%22.5%6 $13.43 1/29/20217,620,000 shares $98.76 million -4.8%23.4%6.4 $12.96 1/15/20218,000,000 shares $77.52 million -22.5%24.6%7.1 $9.69 12/31/202010,320,000 shares $80.60 million +12.2%31.7%9.6 $7.81 12/15/20209,200,000 shares $80.32 million +2.7%28.3%8.8 $8.73 11/30/20208,960,000 shares $61.38 million +0.8%27.5%42.9 $6.85 11/15/20208,890,000 shares $43.83 million +3.3%27.4%43.7 $4.93 10/30/20208,610,000 shares $38.14 million +2.9%26.6%44.7 $4.43 10/15/20208,370,000 shares $45.53 million +0.1%25.8%45.4 $5.44 9/30/20208,360,000 shares $41.88 million +10.4%25.8%45.2 $5.01 9/15/20207,570,000 shares $38.53 million -1.4%23.4%37.1 $5.09 8/31/20207,680,000 shares $37.02 million -2.5%23.7%36.9 $4.82 8/14/20207,880,000 shares $40.98 million -0.1%24.5%37.5 $5.20 RUBY Short Interest - Frequently Asked Questions What is Rubius Therapeutics' current short interest? Short interest is the volume of Rubius Therapeutics shares that have been sold short but have not yet been covered or closed out. As of February 28th, investors have sold 2,800,000 shares of RUBY short. 6.10% of Rubius Therapeutics' shares are currently sold short. Learn More on Rubius Therapeutics' current short interest. What is a good short interest ratio for Rubius Therapeutics? 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. RUBY shares currently have a short interest ratio of 1.0. Learn More on Rubius Therapeutics's short interest ratio. What is a good short interest percentage for Rubius Therapeutics? 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. 6.10% of Rubius Therapeutics' floating shares are currently sold short. Is Rubius Therapeutics' short interest increasing or decreasing? Rubius Therapeutics saw a increase in short interest during the month of February. As of February 28th, there was short interest totaling 2,800,000 shares, an increase of 83.0% from the previous total of 1,530,000 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 Rubius Therapeutics' float size? Rubius Therapeutics currently has issued a total of 90,480,000 shares. Some of Rubius Therapeutics' 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. Rubius Therapeutics currently has a public float of 45,880,000 shares. How does Rubius Therapeutics' short interest compare to its competitors? 6.10% of Rubius Therapeutics' shares are currently sold short. Here is how the short interest of companies in the sector of "medical" compare to Rubius Therapeutics: Finch Therapeutics Group, Inc. (0.01%), AlloVir, Inc. (2.56%), Chromocell Therapeutics Co. (8.70%), NKGen Biotech, Inc. (1.55%), AIM ImmunoTech Inc. (414.92%), Sorrento Therapeutics, Inc. (0.64%), Genocea Biosciences, Inc. (0.33%), Eloxx Pharmaceuticals, Inc. (0.07%), Prime Medicine, Inc. (40.95%), Inhibikase Therapeutics, Inc. (4.13%), Which stocks are the most shorted right now? As of the most recent reporting period, the following stocks had the largest short interest positions: Suncor Energy Inc. ($3.27 billion), Occidental Petroleum Corporation ($2.77 billion), Coinbase Global, Inc. ($2.25 billion), T. Rowe Price Group, Inc. ($2.23 billion), Paramount Global ($1.92 billion), Etsy, Inc. ($1.75 billion), Voya Financial, Inc. ($1.74 billion), CarMax, Inc. ($1.62 billion), Old Dominion Freight Line, Inc. ($1.62 billion), and Royal Caribbean Cruises Ltd. ($1.39 billion). View all of the most shorted stocks. What does it mean to sell short Rubius Therapeutics stock? Short selling RUBY is an investing strategy that aims to generate trading profit from Rubius Therapeutics as its price is falling. 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 Rubius Therapeutics? A short squeeze for Rubius Therapeutics 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 RUBY, which in turn drives the price of the stock up even further. How often is Rubius Therapeutics' 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 RUBY, twice per month. The most recent reporting period available is February, 28 2023. More Short Interest Resources from MarketBeat Related Companies FNCH Short Interest Data ALVR Short Interest Data CHRO Short Interest Data NKGN Short Interest Data AIM Short Interest Data SRNE Short Interest Data GNCAQ Short Interest Data ELOX Short Interest Data PRME Short Interest Data IKT Short Interest Data Short Interest Tools Stocks to Short Largest Short Interest Positions Short Interest Increases Short Interest Decreases Short Interest Reporting Dates This page (NASDAQ:RUBY) was last updated on 8/2/2025 by MarketBeat.com Staff From Our PartnersBuffett to put 90% of his money in this one stock?CPA and CFA says you have WAY too many stocks - just buy these 3 After years working at the biggest accoun...Altimetry | SponsoredHe Called Nvidia at $1.10. Now, He Says THIS Stock Will…The original Magnificent Seven returned 16,894%—turning $7K into $1.18 million. 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