SPRO (Spero Therapeutics) Insider Ownership: 10.78 % (As of Jul. 16, 2026)

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SPRO Spero Therapeutics Inc SPRO
61 GF Score
Price $1.70
GF Value $1.05
Valuation Significantly Overvalued
! 5 Warning Signs
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What is Spero Therapeutics Insider Ownership?

Spero Therapeutics SPRO +0.29% 61 Insider Ownership is 10.78 % as of Jul. 16, 2026. GuruFocus rates SPRO with a GF Score™ of 61/100 and a GF Value™ of $1.05 (Significantly Overvalued). The stock has 5 warning signs investors should review.

Insider ownership is the percentage of shares that are owned by company insiders relative to the total shares outstanding. As of today, Spero Therapeutics's insider ownership is 10.78%.

Institutional Ownership is the percentage of shares that are owned by institutions out of the total shares outstanding. As of today, Spero Therapeutics's Institutional Ownership is 39.98%.

Float Percentage Of Total Shares Outstanding is the percentage of float shares relative to the total shares outstanding. As of today, Spero Therapeutics's Float Percentage Of Total Shares Outstanding is 82.86%.

Spero Therapeutics Insider Ownership Historical Data

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The historical data trend for Spero Therapeutics's Insider Ownership can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

Spero Therapeutics Insider Ownership Chart

Spero Therapeutics Historical Data

The historical data trend for Spero Therapeutics can be seen below:

2025-06-30 2025-07-31 2025-08-31 2025-09-30 2025-10-31 2025-11-30 2026-01-31 2026-02-28 2026-05-31 2026-06-30
Insider Ownership 10.91 10.91 10.84 10.82 10.82 10.74 10.74 11.00 10.66 10.78
SPRO
61GF Score
Spero Therapeutics Inc SPRO
Insider Ownership is just one metric. See GF Score™, valuation, warning signs, and more.
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Spero Therapeutics Insider Ownership Calculation

The percentage of shares that are owned by company insiders relative to the total shares outstanding.

Frequently Asked Questions Learn more about Insider Ownership →
What does a Insider Ownership of 10.78 % mean?
Spero Therapeutics (SPRO) has a Insider Ownership of 10.78 % as of Jul. 16, 2026. Insider ownership equals the percent of shares owned by company insiders relative to total shares. View historical data on Spero Therapeutics and its competitors.
Is Spero Therapeutics' Insider Ownership too high?
Spero Therapeutics' current Insider Ownership is 10.78 %. Overall, Spero Therapeutics has a GF Score™ of 61/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Spero Therapeutics' Insider Ownership compare to VXRT and ADCT?
Spero Therapeutics' Insider Ownership of 10.78 % can be compared against companies in the Biotechnology industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Insider Ownership for a Biotechnology company?
A good Insider Ownership depends on the Biotechnology industry context. However, Insider Ownership should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Insider Ownership mean?
A high Insider Ownership can signal that a stock is expensive relative to its fundamentals. Insider ownership equals the percent of shares owned by company insiders relative to total shares. View historical data on Spero Therapeutics and its competitors. Spero Therapeutics's current Insider Ownership is 10.78 %. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Spero Therapeutics stock overvalued right now?
Based on GuruFocus' analysis, Spero Therapeutics (SPRO) is currently considered Significantly Overvalued. The stock's GF Value™ is $1.05, compared to a current price of $1.70 — trading 61.9% above its estimated fair value. The current Insider Ownership is 10.78 %. Spero Therapeutics' overall GF Score™ is 61/100 with 5 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Insider Ownership calculated?
Insider Ownership is calculated from a company's financial statements. For Spero Therapeutics (SPRO), the current Insider Ownership is 10.78 % as of Jul. 16, 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.

Is Spero Therapeutics (SPRO) Overvalued in 2026?

Based on GuruFocus' analysis, Spero Therapeutics stock appears to be overvalued. The current stock price of $1.70 is trading 61.9% above its estimated GF Value™ of $1.05. GuruFocus considers Spero Therapeutics to be Significantly Overvalued.

Key valuation signals for SPRO:

  • Insider Ownership: 10.78 %
  • GF Value™: $1.05 vs. price of $1.70 (61.9% above fair value)
  • GF Score™: 61/100 with 5 warning signs

No single metric tells the full story. See the SPRO stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.

Spero Therapeutics Business Description

Other Exchanges 2HA:Germany
Address 675 Massachusetts Avenue, 14th Floor, Cambridge, MA, USA, 02139
Spero Therapeutics Inc is a clinical-stage biopharmaceutical firm. It focuses on identifying, developing, and commercializing novel treatments for MDR (Multi-drug-resistant) bacterial infections and rare diseases. The company's product candidate, tebipenem pivoxil hydrobromide or tebipenem HBr, is designed to be an oral carbapenem-class antibiotic for use in adults to treat MDR Gram-negative infections. It is also developing SPR720, a novel oral antibiotic designed for the treatment of a rare, orphan disease caused by pulmonary non-tuberculous mycobacterial infections, or NTM disease. It is also focused on SPR206, a next-generation polymyxin investigational product candidate being developed as an IV-administered medicine to treat MDR Gram-negative infections in the hospital.
61GF Score

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Insider Ownership is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

$1.70
Price
$1.05
GF Value