ARCH Venture Fund IX, L.P. 4

What Happened

• ARCH Venture Partners IX, LLC (reported as a 10% owner) purchased 488,090 shares of Lyell Immunopharma (LYEL) in an open market or private purchase on March 6, 2026. The shares were acquired at $25.61 per share for a total reported value of $12,499,985. This is a purchase (often viewed as a bullish signal) by an institutional investor rather than an executive.

Key Details

• Transaction date: 2026-03-06; Price: $25.61 per share; Shares acquired: 488,090; Total value: $12,499,985.
• Filing date: 2026-03-09 — appears timely given the transaction date.
• Shares owned after transaction: Not specified in the provided excerpt.
• Footnotes: The shares are directly held by ARCH Venture Fund IX, L.P. (and related ARCH entities). Several ARCH entities and named managing directors/committee members are listed in the filing and may be deemed to have beneficial interests under SEC rules, but they disclaim beneficial ownership except to the extent of any pecuniary interest. This Form 4 is one of two reports filed jointly by multiple ARCH funds and individuals relating to the same transaction.

Context

• This is an institutional purchase by a venture fund (ARCH), not a company insider like an officer or director. Institutional buys can signal confidence from investors but do not directly indicate management sentiment.
• No options, exercises, gifts, or tax-withholding items are involved in this reported transaction—it's a straight purchase (transaction code P).