Magnetar Financial LLC 4

What Happened

• Magnetar Financial LLC, identified as a 10% owner (via affiliated Magnetar funds), reported the expiration of multiple short derivative positions (transaction code "E") on June 18, 2026. The filings show a total of 4,000,000 derivative shares disposed through expirations, each with a reported price of $0.00 and aggregate value $0 because the options expired unexercised.
• Footnote F1 explains these were a call and a put entered as part of a collar on August 21, 2025; both options expired for no value on June 18, 2026 because CoreWeave’s closing price on that date was between the call and put strike prices.

Key Details

• Transaction date: June 18, 2026; Form 4 filed June 23, 2026 (reporting period 6/18/2026).
• Instruments: Expiration of short derivative positions (options); reported price $0.00, total derivative shares affected = 4,000,000, total value $0.
• Shares owned after transaction: not specified in the excerpted transactions.
• Notable footnotes: F1 (collar arrangement; options expired unexercised); F2–F15 list the specific Magnetar funds that hold the securities (e.g., Magnetar Longhorn Fund LP, Magnetar SC Fund Ltd, Purpose Alternative Credit Funds, etc.); F4 disclaims beneficial ownership by certain Magnetar entities except to the extent of pecuniary interest.
• Transaction type: Institutional derivative expirations by a 10% owner — not an executive open-market buy/sell.

Context

• These were option expirations that lapsed unexercised, not open-market sales or purchases of CoreWeave stock — no cash changed hands and no new underlying shares were reported issued or sold as part of these transactions.
• Because the reporter is an institutional 10% owner (Magnetar and affiliated funds) and the filing documents the expiration of a collar, this is an administrative derivatives outcome rather than a direct signal about insider sentiment.