Reporting Manager
Kristina Burow
Symbol
MTSR
Shares outstanding
105,212,627 shares
Disclosed Ownership
26,829,220 shares
Ownership
26%
Form type
SCHEDULE 13D
Filing time
10 Feb 2025, 21:30:19 UTC
Date of event
03 Feb 2025
Next filing
14 Nov 2025

Reporting Managers (11)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
ARCH Venture Fund XII, L.P. 26% 26,816,808 0 26,816,808 ARCH Venture Partners XII, L.P. its General Partner 0001906837
ARCH Venture Partners XII, L.P. 26% 26,816,808 0 26,816,808 ARCH Venture Partners XII, LLC its General Partner 0001979765
ARCH Venture Partners XII, LLC 26% 26,816,808 0 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Robert Nelsen, Managing Director 0001979548
ARCH Venture Fund XIII, L.P. 26% 26,816,808 0 26,816,808 ARCH Venture Partners XIII, L.P. its General Partner 0002006772
ARCH Venture Partners XIII, L.P. 26% 26,816,808 0 26,816,808 ARCH Venture Partners XIII, LLC its General Partner 0002016083
ARCH Venture Partners XIII, LLC 26% 26,816,808 0 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director 0002016082
Kristina Burow 26% 26,829,220 12,412 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Kristina Burow 0001569248
Keith Crandell 26% 26,816,808 0 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Keith Crandell 0001219039
Steven Gillis 26% 26,816,808 0 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Steven Gillis 0001229592
Robert Nelsen 26% 26,816,808 0 26,816,808 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Robert Nelsen 0001219042
Paul Berns 8.8% 9,289,858 976,178 8,313,680 /s/ Mark McDonnell ** Mark McDonnell, as Attorney-in-Fact for Paul Berns 0001202769