Investor · England, United Kingdom

Mark Williamson

Open Mark in the network graph →

Filings

14

SEC Form D

Connections

31

co-filers

Capital

$9.2M

across filings

Active

May 2010

to Mar 2026

Most-connected co-filers (31)

John Regan · CHICAGO, IL7 shared Alfred V. Vasconcellos · Lincoln, RI7 shared Daniel Iamicelli · Stamford, CT7 shared Howie Choset · Pittsburgh, PA6 shared Michael Macedonia · Sewickley, PA6 shared Lu Li · Pittsburgh, PA6 shared Keith Thomas · Mars, PA6 shared Rich Humphrey · Sunnyvale, CA5 shared Kevin Gibson · England, United Kingdom2 shared Douglas I. Foy · Waltham, MA2 shared Julien Masanes · England, United Kingdom2 shared P.X. Kelley · Arlington, VA2 shared Malcolm King · England, United Kingdom1 shared Steven Smith · Irvine, CA1 shared David Silverman · San Francisco, CA1 shared Marc Laird · Houston, TX1 shared Adam Laird · Houston, TX1 shared John Jay · Houston, TX1 shared Scott Almy · Houston, TX1 shared Paul Woo · Houston, TX1 shared Michelle Cheung · Palo Alto, CA1 shared Molly S. Curl · Addison, TX1 shared Hanna Wu · San Mateo, CA1 shared Keith .. Laska · Indianapolis, IN1 shared

Recent filings (14)

Cornerstone Capital Bancorp, Inc.Mar 2026 · 7 co-filers$35.0M Pipe Force AI, Inc.Feb 2026 · 4 co-filers$650K Amplify Life Insurance CoDec 2025 · 8 co-filers$8.0M Amplify Life Insurance CoDec 2025 · 8 co-filers$8.0M Pipe Force AI, Inc.Dec 2025 · 14 co-filers$450K Pipe Force AI, Inc.Oct 2025 · 11 co-filers Pipe Force AI, Inc.Oct 2025 · 11 co-filers$36 Pipe Force AI, Inc.Oct 2025 · 11 co-filers$350K Pipe Force AI, Inc.Oct 2025 · 11 co-filers Pipe Force AI, Inc.Oct 2025 · 11 co-filers$37 Hanzo Archives LtdAug 2021 · 13 co-filers$3.0M Hanzo Archives LtdAug 2021 · 13 co-filers$3.0M Hanzo Archives LtdMay 2013 · 5 co-filers$299K Inquisitive Minds IncMay 2010 · 3 co-filers$1.7M Inquisitive Minds IncMay 2010 · 3 co-filers$1.7M Inquisitive Minds IncApr 2009 · 3 co-filers$25K Inquisitive Minds IncMar 2009 · 3 co-filers$1.1M

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