ARCH Venture Fund VII Reports 15.1% Stake in 908 Devices Inc. via Amended Schedule 13G

On May 15, 2026, ARCH Venture Fund VII, L.P., along with its affiliates ARCH Venture Partners VII, L.P. and ARCH Venture Partners VII, LLC, filed an amended Schedule 13G (Amendment No. 5) regarding their holdings in 908 Devices Inc. (MASS). The filing reports that ARCH Venture Fund VII is the record owner of 5,725,045 shares of Common Stock, representing a 15.1% ownership stake based on 37,813,621 shares outstanding as of May 4, 2026. The reporting group includes Managing Directors Keith Crandell, Robert Nelsen, and Clinton Bybee. Keith Crandell holds an additional personal interest through 57,794 vested options, 25,291 fully vested restricted stock units, and 1,086 options vesting within 60 days, bringing his individual beneficial ownership to 5,809,216 shares, or approximately 15.3%. The filing indicates an increase from the previously reported 0% ownership in the provided metadata, though the current filing is an amendment to a long-standing position. All reporting entities share voting and dispositive power over the record shares held by the Fund.