Cerebras Systems is trading 4.38% down at $175.12 on October 1. - Approximately 19.4 million shares became eligible for sale following a lockup expiration on September 30. - Officer filings disclosed planned sales totaling about $84.3 million on September 29-30. - Concerns persist from an unverified September 30 report that OpenAI's newest ultrafast model may be running on Nvidia hardware, not Cerebras systems.