Insiders have sold $296 million of Cerebras stock since June — the CEO and CTO alone sold over $240 million. Cathie Wood’s ARK fund keeps buying. One of them is wrong, and one November date decides who.

Cerebras fell from $206.75 to $166.43 in one week after an unconfirmed research post said OpenAI’s fastest AI tier runs on Nvidia, not Cerebras. This breakdown covers what Sam Altman said in response — and what he didn’t.

Lockups matter: 19.4 million shares unlocked Sep 30, another 19.4 million Oct 14, another Oct 28 — 58.2 million shares total, almost a quarter of the company, with the final lockup Nov 9. Against that sits a $25.4 billion backlog, mostly one OpenAI agreement (750 MW through 2028, over $20 billion), plus about $8.6 billion in cash and investments.

ARK bought 106,941 shares on Aug 13 and 93,290 more on Aug 25 while trimming AMD. Concentration risk is real: in 2025, 86% of revenue came from two customers (MBZUAI 62%, G42 24%), and three customers were 76% of revenue last quarter. Core revenue was $209.9 million (up 103%, a beat) vs GAAP $180.1 million (a miss). At about $164 you’re paying roughly 45x 2026 guided sales vs an average analyst target near $300.

Levels: buy zone $160–165 (June low $160.81); stop adding on a daily close below $160; resistance $184–185 (IPO), then $195, $208–212, and the August high at $262. The plan is staged in thirds around the Oct 28 unlock and Nov 9 / Q3 earnings — not a lump-sum chase.

Educational content only — not financial advice.