Starboard Value LP - 30 Mar 2026 SCHEDULE 13D/A Report for ALGONQUIN POWER & UTILITIES CORP. Common Shares, no par value (AQN)

Filing manager
Starboard Value LP
Reporting owner
Starboard Value LP
Security
ALGONQUIN POWER & UTILITIES CORP. Common Shares, no par value
Beneficially owned shares
57,215,415 shares
Ownership signal CIK-linked ownership evidence from parsed SEC filings. 2 signals
Large-stake signal

Form

SCHEDULE 13D/A

Active or control-oriented beneficial ownership filing.

Ownership

7.4%

Beneficial ownership of this reported class.

Shares

57,215,415 shares

Shares beneficially owned as disclosed.

Event date

30 Mar 2026

Date tied to the ownership event or amendment.

Accepted by SEC

01 Apr 2026

EDGAR acceptance date.

How to read this large-stake filing
  • Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
  • Compare this filing with the holder history and issuer page before treating the percentage as a current position.
  • Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
Class ownership
7.4%
Subject security Names, identifiers, and filing context for this profile. 2 source fields
Symbol
AQN
Shares outstanding
773,181,284 shares
Source evidence Original filing metadata and source links for verification. 5 source fields
SEC form
SCHEDULE 13D/A
Accepted by SEC
01 Apr 2026, 21:45:50 UTC
Event date
30 Mar 2026
Prior SEC filing
14 Mar 2025
Source filing
View source filing

Key filing fact

Starboard Value LP disclosed 7.4% ownership in ALGONQUIN POWER & UTILITIES CORP. Common Shares, no par value (AQN) on 30 Mar 2026.

Key facts

  • Starboard Value LP filed SCHEDULE 13D/A for ALGONQUIN POWER & UTILITIES CORP. Common Shares, no par value (AQN).
  • Disclosed ownership: 7.4%.
  • Date of event: 30 Mar 2026.

Change

  • Previous schedule filing date: 14 Mar 2025.
  • Current filing was accepted on 01 Apr 2026, 21:45.

Research use

  • This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
  • Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.

Evidence

Backed by Schedule 13D/13G

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

View source filing

Reporting persons

Disclosed reporting parties (19)

Names, ownership percentages, 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
Starboard Value LP 7.4% 57,215,415 57,215,415 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value GP LLC, its general partner 0001517137
Starboard Value and Opportunity Master Fund III LP 3.8% 29,048,104 29,048,104 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value A LP, its general partner
Starboard Value and Opportunity S LLC 0.5% 3,429,144 3,429,144 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value LP, its manager 0001519812
Starboard Value and Opportunity C LP 0% 0 0 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value R LP, its general partner 0001571704
Starboard X Master Fund II LP 1.1% 8,424,596 8,424,596 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value R LP, its general partner
Starboard Value R LP 1.1% 8,424,596 8,424,596 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value R GP LLC, its general partner 0001575972
Starboard Value and Opportunity Master Fund L LP 0.2% 1,493,906 1,493,906 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value L LP, its general partner 0001767736
Starboard Value L LP 0.2% 1,493,906 1,493,906 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value R GP LLC, its general partner 0001767773
Starboard Value R GP LLC 1.3% 9,918,502 9,918,502 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory 0001575979
Starboard G Fund, L.P. 1.2% 9,172,365 9,172,365 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value G GP, LLC, its general partner
Starboard Value G GP, LLC 1.2% 9,172,365 9,172,365 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value A LP, its general partner
Starboard Value A LP 5% 38,220,469 38,220,469 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Value A GP LLC, its general partner 0001575998
Starboard Value A GP LLC 5% 38,220,469 38,220,469 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory 0001575974
Starboard Value GP LLC 7.4% 57,215,415 57,215,415 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Principal Co LP, its member 0001517138
Starboard Principal Co LP 7.4% 57,215,415 57,215,415 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory for Starboard Principal Co GP LLC, its general partner 0001517139
Starboard Principal Co GP LLC 7.4% 57,215,415 57,215,415 0 /s/ Lindsey Cara Lindsey Cara, Authorized Signatory 0001517140
Smith Jeffrey C 7.4% 57,215,415 0 57,215,415 /s/ Lindsey Cara Lindsey Cara, Attorney-in-Fact for Jeffrey C. Smith 0001362697
Feld Peter A 7.4% 57,215,415 0 57,215,415 /s/ Lindsey Cara Lindsey Cara, attorney-in-fact for Peter A. Feld 0001410600
Molinelli Gavin 0% 25,995 25,995 0 /s/ Lindsey Cara Lindsey Cara, attorney-in-fact for Gavin T. Molinelli 0001460496
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