Adage Capital Management, L.P. - 31 Mar 2026 SCHEDULE 13G Report for Mountain Lake Acquisition Corp. II Class A Ordinary Shares, par value $0.0001 per share (MLAA)

Filing Manager
Adage Capital Management, L.P.
Reporting Manager
Adage Capital Management, L.P.
Security
Mountain Lake Acquisition Corp. II Class A Ordinary Shares, par value $0.0001 per share
Symbol
MLAA
Shares outstanding
36,971,831 shares
Disclosed Ownership
2,100,000 shares
Ownership
5.7%
Form type
SCHEDULE 13G
Filing time
13 May 2026, 09:30:36 UTC
Date of event
31 Mar 2026
SEC
View on sec.gov

Key filing fact

Adage Capital Management, L.P. disclosed 5.7% ownership in Mountain Lake Acquisition Corp. II Class A Ordinary Shares, par value $0.0001 per share (MLAA) on 31 Mar 2026.

Key facts

  • Adage Capital Management, L.P. filed SCHEDULE 13G for Mountain Lake Acquisition Corp. II Class A Ordinary Shares, par value $0.0001 per share (MLAA).
  • Disclosed ownership: 5.7%.
  • Date of event: 31 Mar 2026.

Change

  • No earlier schedule filing is available for direct comparison.
  • Current filing was accepted on 13 May 2026, 09:30.

Research use

  • This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
  • You can verify ownership claims directly against the original SEC filing.

Evidence

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

See Original Filing

Reporting persons

Reporting managers (3)

Names, ownership, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
Adage Capital Management, L.P. 5.7% 2,100,000 0 2,100,000 /s/ Robert Atchinson By: Adage Capital Partners, L.L.C., its General Partner, By: Robert Atchinson, its Managing Member
Robert Atchinson 5.7% 2,100,000 0 2,100,000 /s/ Robert Atchinson Robert Atchinson, individually
Phillip Gross 5.7% 2,100,000 0 2,100,000 /s/ Phillip Gross Phillip Gross, individually
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