Penny Stocks on the Move: Today’s Top Gainers and Biggest Decliners

On May 28, 2025, the penny stock market witnessed significant fluctuations, with Spero Therapeutics, Inc. leading the top gainers by soaring 244.58%, while InflaRx N.V. emerged as the top decliner, experiencing a steep drop of 59.84%. These movements reflect pivotal developments within each company, influencing investor sentiment and market dynamics.

Top Gainers
Spero Therapeutics, Inc. (SPRO)
Spero Therapeutics, Inc., a pharmaceutical company, saw its stock price surge by 244.58%, ranking first among penny stocks today. The stock reached an intraday high of $2.48 and closed at $2.35. Reports indicate that Spero and GSK halted a Phase 3 trial for a urinary tract infection drug early due to successful outcomes, contributing to the stock's rise. Analysts say the announcement on May 28, 2025, highlighted the drug's pivotal results, fueling investor optimism.

Aspire Biopharma Holdings, Inc. (ASBP)
Aspire Biopharma Holdings, Inc., a prominent player in the pharmaceutical industry, saw its stock skyrocket by an impressive 196.64% today, ranking second in the penny stock market. The stock hit an intraday high of $0.73 before closing at $0.71. Reports indicate that the surge was influenced by Aspire Biopharma's announcement on May 8, 2025, regarding the development update on BUZZ BOMB™, a novel sublingual pre-workout supplement set for launch in the third quarter of 2025. Additionally, analysts say that the company's strategic moves and innovative product pipeline continue to bolster investor confidence.

Signing Day Sports, Inc. (SGN)
Signing Day Sports, Inc., a player in the hotel, restaurant, and leisure industry, experienced a dramatic stock surge of 163.25% today, ranking third among penny stocks. The intraday high reached $4.27, closing at $2.19. Reports indicate that the company's stock soared due to the announcement of a definitive business combination agreement to acquire One Blockchain LLC on May 28, 2025, aiming to establish a public company. Additionally, analysts say the recent binding term sheet to acquire a sports SAAS model application has generated significant investor interest.

Safe & Green Holdings Corp. (SGBX)
Safe & Green Holdings Corp., a company in the building products industry, experienced a remarkable stock surge of 124.23% today, ranking fourth among penny stocks. The stock hit an intraday high of $1.45 and closed at $1.24. Recent developments, dated May 27, indicate that Safe & Green Holdings entered into a multi-unit order agreement, expected to be the first of several throughout 2025. Additionally, reports indicate significant funding and strategic partnerships driving the company's growth and contributing to today's stock surge.

CollPlant Biotechnologies Ltd. (CLGN)
CollPlant Biotechnologies, a leader in the biotechnology industry, saw a significant stock surge of 76.17% today, closing at $3.40 after hitting an intraday high of $3.50, ranking fifth among today's penny stock market movers. Reports indicate that on May 28, 2025, CollPlant announced its first quarter financial results, highlighting strategic advancements in their regenerative and aesthetics medicine sector, contributing to the dramatic rise in stock value.

Top Decliners
InflaRx N.V. (IFRX)
InflaRx N.V., a biopharmaceutical company in the pharmaceutical industry, experienced a significant stock drop today, plummeting by 59.84%, ranking it first in today's penny stock market decline. The stock hit an intraday low of $0.71 and closed at $0.73. Reports from May 28, 2025, indicate that InflaRx's decision to halt its Phase 3 trial for vilobelimab in pyoderma gangrenosum, due to futility, has significantly impacted investor confidence. Analysts say the company's strategic shift to prioritize its resources on INF904 and consider additional cost-saving measures could be a pivotal move for its future financial health.

Patriot National Bancorp, Inc. (PNBK)
Patriot National Bancorp, Inc., a commercial bank, witnessed a sharp decline in its stock value today, dropping by 51.02% and ranking second in the penny stock market's biggest movements. The intraday low was recorded at $1.66, with a closing price of $1.68. Recent developments may have influenced this downturn, as reports indicate that the company raised over $50 million through a private placement. Additionally, CEO David Lowery announced his departure effective April 15 to pursue other opportunities, according to reports from May 25, 2025.

Cemtrex, Inc. (CETX)
Today, Cemtrex, Inc. experienced a sharp decline of 48.76% in its stock value, ranking third among penny stocks with notable dips. Closing at $0.87, just above its intraday low of $0.86, the company, operating in the electronic equipment, instruments, and components industry, is navigating turbulent market waters. Reports indicate that the significant drop was influenced by the company's announcement on May 27, 2025, of a proposed public offering and subsequent pricing of $1.25 million, causing investor trepidation.

Ess Tech, Inc. (GWH)
Ess Tech, Inc., operating in the electrical equipment industry, experienced a sharp decline today with its stock plummeting by 42.64%, ranking fourth in today's penny stock market. The stock hit an intraday low of $1.04 before closing at $1.13. Recent reports indicate that the company, which announced on May 27, 2025, it faces a potential shutdown due to financing difficulties, has lost nearly $250 million over the past three years and reported a first-quarter 2025 earnings miss with an EPS of -$1.50, prompting concerns over its financial stability.

Medicus Pharma Ltd. (MDCX)
Medicus Pharma Ltd., operating in the biotechnology sector, faced a significant stock decline of 33.12% today, ranking fifth in today's penny stock market. The stock reached an intraday low of $3.99 and closed at $4.12. Reports indicate that the company's stock plummeted following the announcement on May 27, 2025, of a strategic acquisition of Antev Ltd., raising concerns among investors about integration risks and potential financial strain. Analysts say that the pricing of a $4.2 million Tier II Regulation A offering on May 25, 2025, further added pressure to the stock amidst dilution fears.