ProMIS Neurosciences (PMN) 28.57% Plunge Driven by Reverse Stock Split to Avert Nasdaq Delisting

The share price of ProMIS Neurosciences (PMN) dropped to a record low today, with an intraday decline of 28.57% so far this month. The selloff intensified after the biotech company announced a 1-for-25 reverse stock split, scheduled to take effect on November 28, 2025, to comply with Nasdaq’s minimum bid price requirement of $1.00 per share. The move aims to avert delisting but has sparked investor concerns over financial stability and operational challenges.

ProMIS disclosed the reverse split following a regulatory deficiency notice issued on January 8, 2025, for failing to maintain the required bid price for 30 consecutive business days. The adjustment will reduce outstanding shares from 53.8 million to 2.15 million, proportionally modifying equity incentives and warrants. Shareholders with fractional shares will receive cash instead of equity, a decision reflecting the company’s liquidity constraints. The premarket price fell 18.8% to $0.341, exacerbating a weak financial outlook marked by a $22.6 million market capitalization and a “WEAK” InvestingPro rating. While the split theoretically raises per-share value, its aggressive 25:1 ratio risks signaling desperation to meet Nasdaq’s December 29 compliance deadline.

The company’s strategic flexibility, including shareholder-approved authority for future share consolidations, introduces further uncertainty. Despite ProMIS’s focus on neurodegenerative disease therapies and its EpiSelect platform for protein misfolding targets, recent stock performance remains decoupled from clinical progress. Investors are instead fixated on regulatory maneuvers and capital structure adjustments, which highlight liquidity pressures and a high debt-to-equity ratio. The reverse split’s dual impact—raising share price while deterring new investors—underscores the precarious balance between compliance and market confidence. With limited visibility on therapeutic advancements, the stock’s trajectory will likely hinge on its ability to navigate short-term regulatory hurdles while preserving long-term scientific credibility.