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Spero Therapeutics (SPRO) Short Interest Ratio & Short Volume

Spero Therapeutics logo
$2.20 0.00 (0.00%)
Closing price 07/2/2026 04:00 PM Eastern
Extended Trading
$2.15 -0.05 (-2.05%)
As of 07/2/2026 07:29 PM Eastern
Extended trading is trading that happens on electronic markets outside of regular trading hours. This is a fair market value extended hours price provided by Massive. Learn more.
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Spero Therapeutics Short Interest Overview

As of June 15, 2026, Spero Therapeutics (SPRO) had a short interest of 1.83 million shares sold short, representing 3.26% of the public float. This marks a 7.33% increase in short interest since the prior report. The short interest ratio (days to cover) is 2.3, meaning it would take 2.3 days of the average trading volume of 1.75 million shares to cover all short positions.

Current Short Interest
1,831,713 shares
Previous Short Interest
1,706,545 shares
Change Vs. Previous Month
7.33%
Dollar Volume Sold Short
$5.33 million
Short Interest Ratio
2.3 Days to Cover
Last Record Date
June 15, 2026
Outstanding Shares
57,900,000 shares
Short Percent of Float
3.26%
Today's Trading Volume
629,508 shares
Average Trading Volume
1,747,616 shares
Today's Volume Vs. Average
36%
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Short Interest ChartDays to Cover ChartShort Percent of Float Chart

SPRO Short Interest Over Time

SPRO Days to Cover Over Time

SPRO Percentage of Float Shorted Over Time

Spero Therapeutics 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
6/15/20261,831,713 shares $5.33 million +7.3%3.3%2.25 $2.91
5/29/20261,706,545 shares $4.83 million +3.6%3.0%1.96 $2.83
5/15/20261,647,297 shares $4.60 million +39.6%3.0%2.61 $2.79
4/30/20261,179,702 shares $2.96 million +59.9%2.2%3.06 $2.51
4/15/2026737,720 shares $1.95 million +21.9%1.3%1.39 $2.64
3/31/2026605,311 shares $1.42 million +12.6%1.1%1.86 $2.34
3/13/2026537,411 shares $1.39 million -6.4%1.0%1.72 $2.58
2/27/2026574,027 shares $1.25 million -19.8%1.1%2.12 $2.17
2/13/2026715,694 shares $1.71 million -24.0%1.3%1.68 $2.39
1/30/2026941,659 shares $2.06 million -9.4%1.8%4.01 $2.19
1/15/20261,039,613 shares $2.50 million +9.8%2.0%4.43 $2.40
12/31/2025946,767 shares $2.21 million -10.4%1.8%3.85 $2.33
12/15/20251,056,013 shares $2.42 million +27.9%2.0%3.51 $2.29
11/28/2025825,698 shares $1.98 million +34.1%1.6%2.14 $2.40
11/14/2025615,735 shares $1.48 million +29.3%1.2%1.05 $2.41
10/31/2025476,137 shares $1.16 million +50.8%0.9%0.31 $2.43
10/15/2025315,700 shares $786.09 thousand -42.6%0.6%0.4 $2.49
9/30/2025549,500 shares $1.03 million +19.8%N/A1 $1.88
9/15/2025458,600 shares $862.17 thousand -9.0%N/A0.7 $1.88
8/31/2025504,000 shares $1.04 million -45.6%0.9%0.5 $2.07
8/15/2025927,200 shares $1.77 million -32.8%N/A0.2 $1.91
7/31/20251,380,000 shares $3.20 million +13.1%2.6%0.3 $2.32
7/15/20251,220,000 shares $3.04 million -28.2%N/A0.3 $2.49
6/30/20251,700,000 shares $4.93 million +5.6%3.2%0.4 $2.90
6/15/20251,610,000 shares $4.56 million -53.7%3.0%0.4 $2.83
5/31/20253,480,000 shares $8.98 million +446.6%6.7%0.9 $2.58
5/15/2025636,700 shares $414.62 thousand -1.3%1.2%5 $0.65
4/30/2025645,200 shares $424.54 thousand -19.5%N/A5 $0.66
4/15/2025801,300 shares $596.49 thousand +60.9%1.5%4.8 $0.74
3/31/2025498,100 shares $358.63 thousand +13.9%1.0%2.6 $0.72
3/15/2025437,300 shares $342.14 thousand +3.0%0.8%2.2 $0.78
2/28/2025424,700 shares $329.40 thousand -1.1%0.8%2 $0.78
2/15/2025429,600 shares $350.12 thousand +14.0%0.8%1.9 $0.82
1/31/2025376,800 shares $322.77 thousand +6.4%N/A1.5 $0.86
1/15/2025354,100 shares $317.70 thousand -14.2%N/A1.2 $0.90
12/31/2024412,600 shares $424.98 thousand -8.6%N/A1.4 $1.03
12/15/2024451,200 shares $482.78 thousand -8.6%N/A1.7 $1.07
11/30/2024493,800 shares $562.93 thousand -9.7%N/A2 $1.14
11/15/2024546,800 shares $645.22 thousand -12.5%N/A2.3 $1.18
10/31/2024625,200 shares $769.00 thousand +61.5%N/A3 $1.23
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10/15/2024387,100 shares $464.52 thousand +0.7%N/A3.2 $1.20
9/30/2024384,300 shares $514.96 thousand -0.2%N/A3 $1.34
9/15/2024385,200 shares $527.72 thousand -5.8%N/A3.4 $1.37
8/31/2024409,100 shares $560.47 thousand +8.6%N/A3.1 $1.37
8/15/2024376,700 shares $455.81 thousand +5.8%N/A2.9 $1.21
7/31/2024355,900 shares $501.82 thousand -8.8%N/A2.6 $1.41
7/15/2024390,300 shares $563.98 thousand -7.1%N/A2.7 $1.45
6/30/2024420,000 shares $546 thousand -3.3%N/A2.5 $1.30
6/15/2024434,200 shares $590.51 thousand -10.3%N/A2.3 $1.36
5/31/2024483,900 shares $687.14 thousand -2.1%N/A1.7 $1.42
5/15/2024494,200 shares $800.60 thousand +5.6%N/A1.6 $1.62
4/30/2024468,100 shares $664.70 thousand -8.8%N/A1.5 $1.42
4/15/2024513,200 shares $785.20 thousand -21.5%N/A1.6 $1.53
3/31/2024653,800 shares $1.12 million +6.5%N/A2.1 $1.72
3/15/2024613,900 shares $1.10 million +8.9%N/A2 $1.79
2/29/2024564,000 shares $930.60 thousand -8.9%N/A2.8 $1.65
2/15/2024619,000 shares $940.88 thousand -12.5%N/A3.2 $1.52
1/31/2024707,100 shares $1.07 million +4.0%N/A3.8 $1.52
1/15/2024680,200 shares $986.29 thousand -13.8%N/A4 $1.45
12/31/2023789,000 shares $1.16 million -19.2%N/A4.5 $1.47
12/15/2023976,500 shares $1.26 million -9.6%N/A6 $1.29
11/30/20231,080,000 shares $1.23 million -4.4%N/A6.2 $1.14
11/15/20231,130,000 shares $1.29 million -10.3%N/A4.7 $1.14
10/31/20231,260,000 shares $1.36 million -3.1%N/A4.8 $1.08
10/15/20231,300,000 shares $1.47 million -3.7%N/A4.1 $1.13
9/30/20231,350,000 shares $1.63 million -5.6%N/A4.2 $1.21
9/15/20231,430,000 shares $1.83 million +25.4%N/A4.3 $1.28
8/31/20231,140,000 shares $1.71 million No ChangeN/A3.2 $1.50
8/15/20231,140,000 shares $1.53 million -2.6%N/A3.8 $1.35
7/31/20231,170,000 shares $1.91 million No ChangeN/A3.9 $1.63
7/15/20231,170,000 shares $1.77 million -4.9%N/A4.2 $1.51
6/30/20231,230,000 shares $1.78 million +40.4%N/A4 $1.45
6/15/2023876,300 shares $1.38 million -0.6%N/A1.8 $1.57
5/31/2023881,800 shares $1.53 million -9.5%N/A1.7 $1.74
5/15/2023974,400 shares $1.82 million -32.8%N/A1.7 $1.87
4/30/20231,450,000 shares $2.57 million -21.6%N/A2.5 $1.77
4/15/20231,850,000 shares $3.18 million +17.1%N/A3.3 $1.72
3/31/20231,580,000 shares $2.29 million +67.6%N/A2.8 $1.45
3/15/2023942,700 shares $1.39 million +142.0%N/A2.1 $1.47
2/28/2023389,500 shares $576.46 thousand +35.5%N/A0.9 $1.48
2/15/2023287,400 shares $514.45 thousand -38.6%N/A0.7 $1.79
1/31/2023468,200 shares $866.17 thousand -29.9%N/A0.8 $1.85
1/15/2023667,900 shares $1.34 million -21.4%N/A1.1 $2.00
12/30/2022849,400 shares $1.47 million -14.6%N/A1.1 $1.73
12/15/2022994,200 shares $1.69 million -23.5%N/A0.4 $1.70
11/30/20221,300,000 shares $2.52 million -13.9%N/A0.2 $1.94
11/15/20221,510,000 shares $2.84 million +22.8%5.5%0.2 $1.88
10/31/20221,230,000 shares $2.41 million -15.8%4.5%0.2 $1.96
10/15/20221,460,000 shares $2.89 million -32.4%5.4%0.2 $1.98
9/30/20222,160,000 shares $4.32 million +177.9%8.0%0.3 $2.00
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9/15/2022777,200 shares $753.88 thousand +182.0%2.9%0.1 $0.97
8/31/2022275,600 shares $222.38 thousand -32.9%1.0%0.1 $0.81
8/15/2022410,600 shares $371.06 thousand +1.1%1.5%1.3 $0.90
7/31/2022406,100 shares $297.35 thousand -27.2%1.6%1.1 $0.73
7/15/2022557,800 shares $440.66 thousand +34.9%2.3%0.8 $0.79
6/30/2022413,600 shares $306.48 thousand -70.9%1.7%0.6 $0.74
6/15/20221,420,000 shares $1.36 million -9.0%5.8%1.9 $0.96
5/31/20221,560,000 shares $1.84 million -5.5%6.4%2.3 $1.18
5/15/20221,650,000 shares $2.82 million -55.3%6.8%2.6 $1.71
4/30/20223,690,000 shares $17.93 million +6.7%14.6%6.3 $4.86
4/15/20223,460,000 shares $21.14 million +6.5%13.7%16.7 $6.11
3/31/20223,250,000 shares $28.28 million +4.2%13.1%16.5 $8.70
3/15/20223,120,000 shares $25.40 million +5.4%12.6%18.6 $8.14
2/28/20222,960,000 shares $28.42 million +5.7%11.9%20.8 $9.60
2/15/20222,800,000 shares $27.94 million +12.0%11.3%19.6 $9.98
1/31/20222,500,000 shares $29.68 million +4.6%10.1%18.6 $11.87
1/15/20222,390,000 shares $31.55 million +4.4%9.4%21.1 $13.20
12/31/20212,290,000 shares $36.66 million -1.7%9.0%23.2 $16.01
12/15/20212,330,000 shares $30.64 million -0.9%9.2%24.5 $13.15
11/30/20212,350,000 shares $33.49 million -2.5%9.3%23.9 $14.25
11/15/20212,410,000 shares $39.55 million -3.6%9.5%22.4 $16.41
10/29/20212,500,000 shares $43.90 million No Change9.9%21 $17.56
10/15/20212,500,000 shares $42.55 million -1.2%9.9%21.4 $17.02
9/30/20212,530,000 shares $46.58 million -1.9%10.0%20.4 $18.41
9/15/20212,580,000 shares $47.81 million -4.1%10.2%16.4 $18.53
8/31/20212,690,000 shares $51.78 million +1.9%10.9%15.8 $19.25
8/13/20212,640,000 shares $35.69 million No Change10.7%16.5 $13.52
7/30/20212,640,000 shares $35.22 million No Change11.6%17 $13.34
7/15/20212,640,000 shares $37.73 million +10.0%12.1%16.6 $14.29

SPRO Short Interest - Frequently Asked Questions

Short interest is the volume of Spero Therapeutics shares that have been sold short but have not yet been closed out or covered. As of June 15th, traders have sold 1,831,713 shares of SPRO short. 3.26% of Spero Therapeutics' shares are currently sold short. Learn More on Spero Therapeutics' 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. SPRO shares currently have a short interest ratio of 2.3. Learn More on Spero Therapeutics'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. 3.26% of Spero Therapeutics' floating shares are currently sold short.

Spero Therapeutics saw a increase in short interest in the month of June. As of June 15th, there was short interest totaling 1,831,713 shares, an increase of 7.3% from the previous total of 1,706,545 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.

3.26% of Spero Therapeutics' shares are currently sold short. Here is how the short interest of companies in the industry of "pharmaceutical products" compare to Spero Therapeutics: Silence Therapeutics PLC Sponsored ADR (4.51%), Cabaletta Bio, Inc. (17.20%), Ovid Therapeutics (6.83%), Neurogene Inc. (25.42%), Valneva SE Sponsored ADR (0.21%), Evommune, Inc. (11.85%), AgomAb Therapeutics NV (2.95%), SOPHiA GENETICS SA (0.33%), Nuvectis Pharma, Inc. (8.28%), Rezolute, Inc. (16.83%),

As of the most recent reporting period, the following stocks had the largest short interest positions: SPDR S&P 500 ETF Trust ($77.25 billion), Invesco QQQ ($51.70 billion), iShares Russell 2000 ETF ($25.75 billion), Sandisk Corporation ($23.00 billion), Western Digital Corporation ($17.29 billion), Nebius Group N.V. ($13.25 billion), SPDR S&P Biotech ETF ($10.78 billion), KLA Corporation ($10.45 billion), Salesforce Inc. ($9.71 billion), and VanEck Semiconductor ETF ($9.01 billion). View all of the most shorted stocks.

Short selling SPRO is an investing strategy that aims to generate trading profit from Spero 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.

A short squeeze for Spero 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 SPRO, 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 SPRO, twice per month. The most recent reporting period available is June, 15 2026.

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

  • 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:SPRO) was last updated on 6/25/2026 by MarketBeat.com Staff.
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