Avoid the stress of overpaying for a stock or missing an opportunity by using the right tools and insights to evaluate Spero Therapeutics, Inc. before investing.

In this article, we go over a few key elements for understanding Spero Therapeutics, Inc.’s stock price such as:

• Spero Therapeutics, Inc.’s current stock price and volume
• Why Spero Therapeutics, Inc.’s stock price changed recently
• Upgrades and downgrades for SPRO from analysts
• SPRO’s stock price momentum as measured by its relative strength

About Spero Therapeutics, Inc. (SPRO)

Before we jump into Spero Therapeutics, Inc.’s stock price, history, target price and what caused it to recently , let’s take a look at some background.

Spero Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on identifying and developing novel treatments for multi-drug resistant (MDR) bacterial infections and rare diseases in the United States. The company’s product candidates include Tebipenem HBr (tebipenem pivoxil hydrobromide), an oral carbapenem-class antibiotic to treat complicated urinary tract infections, including pyelonephritis for adult patients, which has completed second Phase 3 trial. It has license agreement with Meiji Seika Pharma Co., Ltd. to develop, manufacture, and commercialize tebipenem pivoxil and tebipenem HBr; and Everest Medicines to develop, manufacture, and commercialize SPR206 in Greater China, South Korea, and Southeast Asian countries. Spero Therapeutics, Inc. was incorporated in 2013 and is headquartered in Cambridge, Massachusetts.

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Spero Therapeutics, Inc.’s Stock Price as of Market Close

As of June 29, 2026, 4:00 PM, CST, Spero Therapeutics, Inc.’s stock price was $2.260.

Spero Therapeutics, Inc. is 0% from its previous closing price of $2.260.

During the last market session, Spero Therapeutics, Inc.’s stock traded between $2.250 and $2.330. Currently, there are approximately 57.28 million shares outstanding for Spero Therapeutics, Inc..

Spero Therapeutics, Inc.’s price-earnings (P/E) ratio is currently at 8.7, which is low compared to the Biotechnology industry median of 19.4. The price-earnings ratio gauges market expectation of future performance by relating a stock’s current share price to its earnings per share.

Spero Therapeutics, Inc. Stock Price History

Spero Therapeutics, Inc.’s (SPRO) price is currently down 20.14% so far this month.

During the month of June, Spero Therapeutics, Inc.’s stock price has reached a high of $3.070 and a low of $1.950.

Over the last year, Spero Therapeutics, Inc. has hit prices as high as $3.220 and as low as $1.800. Year to date, Spero Therapeutics, Inc.’s stock is down 3%.

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What Caused Spero Therapeutics, Inc. Stock’s Price to ?

Stock prices are primarily based on seller supply and buyer demand. But have you ever wondered about what other factors affect a stock's price?

When an analyst changes their opinion of a stock by upgrading or downgrading their rating, it often leads to a sudden stock price adjustment. As of June 29, 2026, there were analysts who downgraded Spero Therapeutics, Inc.’s stock and analysts who upgraded over the last month.

Additionally, you'll want to evaluate Spero Therapeutics, Inc.’s financial health and valuation. Investors can use AAII's Value Grade, which combines six key valuation metrics like P/E and P/S ratios for a comprehensive analysis to conduct analysis on Spero Therapeutics, Inc.’s valuation and financial health. This approach mitigates the limitations of single-metric evaluations.

Spero Therapeutics, Inc.’s current valuation based on AAII’s Value Grade is a B, which means it is considered to be Value.

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Lastly, news and media coverage as well as recent press reports about the company or its industry may cause stock prices to fluctuate. You can check out the most recent news articles about Spero Therapeutics, Inc. (SPRO) by visiting AAII Stock Evaluator.

Relative Price Strength of Spero Therapeutics, Inc.

Relative price strength measures a stock's performance against the market, helping investors identify stocks that are outperforming benchmarks.

For AAII’s Momentum Grade, a weighted relative price strength is calculated. Follow this link to learn more about the Momentum Grade.

As of June 29, 2026, Spero Therapeutics, Inc. has a weighted four-quarter relative price strength of -9.00%, which translates to a Momentum Score of 28 and is considered to be Weak.

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Spero Therapeutics, Inc. Stock Price: Bottom Line

As of June 29, 2026, Spero Therapeutics, Inc.’s stock price is $2.260, which is 0% from its previous closing price.

AAII advises against making stock decisions based solely on price or past returns. Instead, consider a variety of metrics, fundamentals, and analytics to evaluate a stock like Spero Therapeutics, Inc. stock prices are influenced by market supply and demand and offer just a snapshot of a company's overall health.

Subscribing to AAII's A+ Investor provides access to comprehensive analytics and insights for confident investing.