Cerebras stock hits post-IPO low, down 20% for the week

Cerebras shares fell nearly 20% this week to $166.43, their lowest since the May IPO. The drop followed a SemiAnalysis report that OpenAI will power its "Ultrafast" mode for GPT-6.1 Sol with Nvidia GPUs instead of Cerebras hardware, compounded by lockup expiration and insider selling.

• Cerebras lost OpenAI's Ultrafast workload for GPT-6.1 Sol to Nvidia
• Shares closed at $166.43, about half the first-day price
• Market cap fell from $95 billion to just over $39 billion
• 19.4 million shares (8% of total) unlocked; executives sold over $240 million