Frank Thomas Buys 20,000 Shares of Spero Therapeutics

Frank Thomas, an insider at Spero Therapeutics, Inc. (NasdaqGS: SPRO), purchased 20,000 shares of the company on June 23, 2026. This insider buying activity was not part of a pre-arranged trading plan.

What Changed in Frank Thomas's Spero Therapeutics Position

Frank Thomas's acquisition of 20,000 shares marks a notable insider transaction at Spero Therapeutics. The specifics of the transaction, including the price paid, were not disclosed, but it highlights insider confidence in the company's prospects.

Other Institutional Activity in Spero Therapeutics

Vanguard Capital Management LLC opened a new position in Spero Therapeutics, acquiring 1,799,880 shares valued at approximately $4.21 million. Renaissance Technologies LLC reduced its holdings by 90,287 shares, leaving it with 1,189,235 shares worth about $2.78 million, reflecting a 7.1% decrease. Two Sigma Investments, LP significantly increased its stake by 513,061 shares, ending with 885,631 shares valued at around $2.07 million.

Spero Therapeutics, Inc. Stock Up 68.3%

Shares of Spero Therapeutics traded near $2.02 on Friday. The company has a market cap of approximately $116.9 million and a P/E ratio of 7.48. Its beta is 1.456, indicating higher volatility compared to the market. The stock's 52-week range is between $1.80 and $3.22, with a 50-day moving average of $2.63 and a 200-day moving average of $2.40. Spero Therapeutics maintains a strong liquidity position with a current ratio of 10.50 and a quick ratio of 10.23.

Recent Earnings

For its most recent earnings, Spero Therapeutics reported revenue of $61.19 million, although it experienced a revenue decline of 95.6%. The company posted a net margin of 24.9% and a return on equity of 35.1%. Its earnings per share were $0.27. The next earnings report is expected on May 13, 2026.

Insider Buying and Selling at Spero Therapeutics, Inc.

On the same day as Frank Thomas's purchase, other insiders, including Jackson Scott Thomas, John Pottage Jr., Milind Deshpande, Cynthia Smith, and Patrick V.J.J. Vink, each bought 20,000 shares. These transactions were also not part of pre-arranged trading plans.

Analysts Set New Price Targets

On January 30, 2025, HC Wainwright & Co. reiterated its buy rating for Spero Therapeutics with a price target of $5.00. The consensus among analysts is a hold recommendation, with a mean price target of $4.00.

About Spero Therapeutics

Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company based in Cambridge, Massachusetts. It focuses on developing treatments for multi-drug resistant bacterial infections and rare diseases. The company's lead product candidate is Tebipenem HBr, an oral antibiotic for complicated urinary tract infections. Spero has collaborations with Meiji Seika Pharma Co., Ltd., and Everest Medicines for the development and commercialization of its products in various regions.

Bottom Line

Frank Thomas's recent purchase of Spero Therapeutics shares highlights insider interest in the company. Investors often watch insider transactions as a signal of insider confidence. It's important to remember that insider buys and sells can occur for many reasons, and these transactions are reported after the fact. Spero Therapeutics continues to develop its pipeline, and analysts have mixed views on the stock.