CAIN CHRISTOPHER W. 4

What Happened
Christopher W. Cain, a director of Jade Biosciences (JBIO), was granted a derivative award on 2026-06-09 giving a right to 34,843 shares. The grant shows $0 cash paid and is reported as an award/other acquisition (derivative) rather than an open-market purchase or sale.

Key Details

• Transaction date: 2026-06-09; filing date: 2026-06-11 (timely Form 4 filing).
• Award size: option/right for 34,843 shares; reported acquisition price $0.00.
• Vesting: vests in full on the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting, subject to continued service (Footnote F1).
• Beneficial ownership: the option is held for one or more investment vehicles managed by Fairmount Funds Management LLC; Mr. Cain disclaims beneficial ownership and must turn over net cash/stock to the Fairmount Fund(s) (Footnote F2). Fairmount likewise disclaims beneficial ownership except for pecuniary interest.
• Shares owned after the transaction: not specified in the filing.

Context
This filing reports an equity award (an option/derivative grant), not an immediate stock purchase or sale. The option vests in the future and, per the filing, is held for Fairmount-managed funds rather than for Mr. Cain personally, so the report reflects the grant of rights rather than a direct personal stake being taken or sold.