CoreWeave Inc. executives sold over $1 billion in stock following the end of the lockup period in mid-August, making them among the top ten insider sellers in Q3. This marked the first opportunity for insiders to sell since the company's IPO in March, which resulted in four new billionaires. The company's stock has surged over 250% since the IPO. Director Jack Cogen sold $477 million in shares, while co-founder Brannin McBee sold $426 million, both under pre-arranged 10b5-1 plans. Additionally, CoreWeave's largest institutional shareholder, Magnetar Financial LLC, sold nearly $1.9 billion in stock during the same period, though it retains over 20% of the company's Class A shares. A CoreWeave representative declined to comment on the sales.