LAMPERT MARK N 4

What Happened

• BVF Partners L.P. (part of a reporting group that collectively owns >10% of XOMA) converted derivative securities into a total of 5,003,000 shares of XOMA common stock on 2026-05-14. The conversions were recorded at $4.03 per share, for an aggregate value of $20,162,090.
• The Form 4 also reports matching zero-dollar “dispositions” of small derivative lots (2,313; 1,506; 412; 772), as recorded in the filing in connection with the conversions. The filing was submitted jointly by multiple related BVF entities and individuals.

Key Details

• Transaction date: 2026-05-14 (Period of Report); Form filed 2026-05-18.
• Price and value: 5,003,000 shares acquired at $4.03 per share; total reported value $20,162,090.
• Shares owned after transaction: not specified in the provided excerpt; the reporting group is disclosed as a >10% beneficial owner (see footnote F1).
• Notable footnotes: joint filing by several BVF entities and Mark N. Lampert (F1); transactions exempt from Section 16(b) under Rule 16b‑6(b) (F2); Series X Convertible Preferred Stock are exercisable immediately and have no expiration date (F7).
• Timeliness: Form 4 was filed 4 days after the transaction date (file date 2026-05-18 for a 2026-05-14 transaction); the filing does not show a late-report designation.

Context

• This is an institutional conversion by a 10% holder (not an individual executive trade). Conversions of convertible preferred/derivative securities into common stock are a structural transaction (not an open-market purchase) and can increase the public float.
• The filing does not indicate any immediate sale of the converted shares; no open-market sales of common stock by the reporting persons are recorded on this Form 4.