Investor · Waltham, MA

David Southwell

Open David in the network graph →

Filings

4

SEC Form D

Connections

27

co-filers

Capital

$144.6M

across filings

Active

Jul 2019

to Sep 2025

Most-connected co-filers (27)

Christoph Westphal · Boston, MA2 shared Timothy J. Barberich · Concord, MA2 shared Robert D. Mittendorff · Seattle, WA1 shared Sandra E. Peterson · New York, NY1 shared Samuel Z. Bakhoum · New York, NY1 shared Douglas Fambrough · Boston, MA1 shared Nandita Shangari · San Diego, CA1 shared Arjun Balar · NEW YORK, NY1 shared Jill Goldstein · NEW YORK, NY1 shared Jerrold Rosenbaum · Waltham, MA1 shared Richard Simon · Waltham, MA1 shared Lea Hachigian · Boston, MA1 shared Doug Fambrough · Waltham, MA1 shared Brian Silver · Waltham, MA1 shared Ittai Harel · Waltham, MA1 shared Robert Crane · Cambridge, MA1 shared Ellie Mcguire · Cambridge, MA1 shared Andrew Hedin · Cambridge, MA1 shared David Nicholson · Culver City, CA1 shared Steve Kraus · Minneapolis, MN1 shared Ryan Katz · Rockville, MD1 shared Balkrishan Gill · Philadelphia, PA1 shared Alexandra Glucksmann · Cambridge, MA1 shared Hannes Smarason · MOUNTAIN VIEW, CA1 shared

Recent filings (4)

Volastra Therapeutics, Inc.Sep 2025 · 17 co-filers$30.1M Volastra Therapeutics, Inc.Sep 2025 · 17 co-filers$30.1M Sensorium Therapeutics, Inc.Feb 2025 · 13 co-filers$38.5M Sensorium Therapeutics, Inc.Feb 2025 · 13 co-filers$38.5M TScan Therapeutics, Inc.Jan 2021 · 15 co-filers$100.0M TScan Therapeutics, Inc.Jan 2021 · 15 co-filers$100.0M TScan Therapeutics, Inc.Jul 2019 · 13 co-filers$23.3M TScan Therapeutics, Inc.Jul 2019 · 13 co-filers$23.3M

Derived from public SEC Form D (Reg D) filings; entities resolved probabilistically. See David in the interactive graph →