Magnetar Financial LLC 4

What Happened
Magnetar Financial LLC (a 10% owner / investment adviser to several Magnetar funds) reported the expiration of multiple short derivative positions tied to CoreWeave Class A common stock on March 20, 2026. The expired positions in aggregate covered 3,162,474 shares and expired unexercised for no value (transaction proceeds $0). Per the filing, these expirations resulted from a collar arrangement (call and put options entered Aug 15, 2025) where the stock closed between the call and put strike prices on the expiration date.

Key Details

• Transaction date: March 20, 2026. All expirations reported as having $0 value.
• Total shares affected: 3,162,474 shares across multiple derivative contracts. Total proceeds: $0.
• Shares owned after transaction: Not specified in the information provided.
• Related footnotes: The options were part of a collar entered Aug 15, 2025; both call and put expired unexercised and for no value (closing price between strikes). The filing identifies Magnetar Financial as adviser/manager to multiple Magnetar funds that hold the securities (Magnetar Capital Master Fund, CW Opportunity LLC, Magnetar Alpha Star Fund LLC, Magnetar Lake Credit Fund LLC). The various entities disclaim beneficial ownership except to the extent of pecuniary interest.
• Filing timeliness: Report filed with period date same as transaction (Mar 20, 2026); no late filing indicated.

Context
This filing reports derivative expirations, not open-market sales or purchases of stock. When options in a collar expire unexercised for no value, no shares change hands and no cash is exchanged as a result of those expirations. Because Magnetar is a 10% institutional owner and investment adviser to funds, this is institutional derivative activity rather than an executive or insider personal trade — useful for understanding institutional exposure but not necessarily a signal about management sentiment.