Serve Robotics is trading 10.1% lower at $3.91, with no clear immediate reason identified. - No company-specific announcement or clear catalyst appeared in available reporting for the October 12, 2026 decline. - Recent coverage cited reduced 2026 revenue guidance from $26 million to $9–$10 million after expected Uber delivery-volume growth failed to materialize; this is prior context, not a confirmed explanation. - Indexes were mixed: Nasdaq down 0.47%, Dow up 0.36%; market context does not establish a broad-market cause.