AI mania tanks CoreWeave’s Core Scientific acquisition — it buys Python notebook Marimo (techcrunch.com)

Core Scientific shareholders voted down CoreWeave’s all‑stock takeover—an offer that was valued at about $9 billion when announced—after major holder Sina Toussi of Two Seas Capital recommended a “no” vote. Toussi argued Core Scientific, which emerged from bankruptcy in January 2024, could capture much higher AI‑infrastructure valuations on its own; investors agreed, sending Core Scientific’s market cap up to roughly $6.6 billion after the defeat. The deal collapse follows an existing $10 billion, 12‑year capacity agreement between the two firms and comes amid CoreWeave’s meteoric rise (its market value has jumped from roughly $14B at IPO to about $66B), driven by a pivot from crypto mining to hosting AI workloads and close ties with Nvidia. CoreWeave didn’t pause its AI push: it immediately acquired Marimo, an open‑source Jupyter‑style Python notebook startup (PitchBook estimates ~$5M raised). Notebooks are central developer tooling for interactive data analysis and AI app development, so Marimo helps CoreWeave move up the stack from pure infrastructure into developer platforms and app building—a higher‑margin, more defensible position. The episode underscores intense investor optimism — and risk — in AI infrastructure valuations, and signals continued consolidation where data‑center operators are buying developer tools to capture more value across the AI stack.