Spero Therapeutics (SPRO) Insider Frank Thomas Buys 20,000 Shares

Insider Frank Thomas recently bought 20,000 shares of Spero Therapeutics, Inc. (SPRO) on June 23, 2026, with a total value of approximately $40,400 based on the recent price of $2.02 per share. This transaction highlights an active period for insiders at the company, which is focused on developing new treatments for multi-drug resistant infections and rare diseases.

Inside Frank Thomas's Trade

Frank Thomas acquired 20,000 shares in a direct purchase, reflecting his confidence in Spero Therapeutics. This brings the company's insider trading into focus, especially as other insiders also made trades on the same day. It's part of a wave of buying activity, with notable acquisitions from insiders like Kathleen Tregoning and Cynthia Smith on the same date, indicating a collective belief in the company's future prospects.

Other Institutional Activity in Spero Therapeutics

A few significant institutional players are also holding positions in Spero Therapeutics. Vanguard Capital Management LLC grew its holdings by 236,327 shares, totaling 2,036,226 shares worth about $2.3 million. Meanwhile, Renaissance Technologies, LLC reduced its position by 241,287 shares, ending with 947,904 shares valued at approximately $1.1 million. Other institutions like GSK plc and Pfizer Inc have not changed their holdings recently, maintaining shares valued at about $10.2 million and $2.6 million, respectively.

Spero Therapeutics, Inc. Stock Up 78.8%

As of Friday, the shares of Spero Therapeutics are trading at $2.02, showing substantial movement from its 52-week low of $1.08. The stock is well below its 52-week high of $3.08, suggesting potential upside as insiders increase their stakes. The stock also trades above its 50-day moving average of $1.26, which could indicate positive momentum.

Recent Earnings

Spero Therapeutics reported revenue of approximately $47.00 million, with an earnings per share (EPS) of $0.14. The company has experienced a net margin of 15.71% and a return on equity (ROE) of 19.17%. The next earnings report is expected on November 12, 2026.

Insider Buying and Selling at Spero Therapeutics, Inc.

Several insiders have recently bought shares in Spero Therapeutics. Kathleen Tregoning purchased 10,000 shares on June 23, 2026. Vink Patrick V.J.J. also bought 20,000 shares on the same day, as did Cynthia Smith and Milind Deshpande, each acquiring 20,000 shares. All of these transactions indicate a strong belief in the company’s future.

Analysts Set New Price Targets

On September 14, 2026, HC Wainwright & Co. maintained a 'Buy' rating on Spero Therapeutics, increasing its price target from $5.00 to $6.00. The consensus among analysts is positive, reflecting confidence in the company's prospects.

About Spero Therapeutics

Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company based in Cambridge, MA. It focuses on developing innovative treatments for multi-drug resistant bacterial infections and rare diseases. The company's leading product candidate is Tebipenem HBr, aimed at treating complicated urinary tract infections in adults.

Bottom Line

Investors should watch for the upcoming earnings report on November 12, 2026, as the company continues to garner insider support amid a broader context of institutional investment. The recent trading activity from insiders suggests a strong belief in the company's future, although the 13F filings may not reflect current positions due to the reporting lag.