Westfield Capital reports 4.99% stake in IMAX (IMAX) on Schedule 13G/A

Rhea-AI Filing Summary

IMAX CORP amendment to a Schedule 13G/A reports that Westfield Capital Management Company, L.P. beneficially owns 2,737,381 shares of IMAX common stock, representing 4.99% of the class. The filing shows sole voting power for 2,604,711 shares and sole dispositive power for 2,737,381 shares.

Insights

Institutional Ownership Analyst

Large shareholder reports sub-5% stake with full dispositive control.

Westfield Capital discloses ownership of 2,737,381 shares, equal to 4.99% of outstanding common stock. The filing attributes sole voting power over 2,604,711 shares, indicating practical control over voting of most held shares.

Timing information: the cover date is 05/31/2026 and signature dated 06/03/2026. Subsequent filings will show any material changes in stake.

Corporate Governance Specialist

Disclosure clarifies voting and dispositive authorities for an under-5% holder.

The filing lists specific voting and dispositive powers rather than shared authority, which is relevant for governance monitoring and proxy considerations. The reported 4.99% ownership meets the filing threshold for passive/other reporting under schedule rules.

Cash‑flow treatment and any trading intent are not stated in the excerpt.

Key Figures

Beneficially owned shares: 2,737,381 shares Percent of class: 4.99% Sole voting power: 2,604,711 shares +3 more

6 metrics

Beneficially owned shares 2,737,381 shares Amount beneficially owned per amendment

Percent of class 4.99% Percent of IMAX common stock reported

Sole voting power 2,604,711 shares Number with sole power to vote reported

Sole dispositive power 2,737,381 shares Number with sole power to dispose reported

CUSIP 45245E109 CUSIP for IMAX common stock on filing cover

Cover date / Signature date 05/31/2026 / 06/03/2026 Cover date and signature date shown on amendment

Key Terms

Schedule 13G/A, Beneficially owned, Sole dispositive power, Sole voting power

4 terms

Schedule 13G/A regulatory

"amendment to a Schedule 13G/A reports that Westfield Capital beneficially owns"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficially owned financial

"Amount beneficially owned: 2,737,381 (b) Percent of class: 4.99%"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

Sole dispositive power regulatory

"Sole power to dispose or to direct the disposition of: 2,737,381"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

Sole voting power regulatory

"Sole power to vote or to direct the vote: 2,604,711"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

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SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

IMAX CORP

(Name of Issuer)

Common Stock

(Title of Class of Securities)

45245E109

(CUSIP Number)

05/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 45245E109

1

Names of Reporting Persons

Westfield Capital Management Company, L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

MASSACHUSETTS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,604,711.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,737,381.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

4.99 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: IMAX CORP
(b)	Address of issuer's principal executive offices: 2525 SPEAKMAN DRIVE, MISSISSAUGA, ONTARIO, CANADA L5K 1B1
Item 2.
(a)	Name of person filing: Westfield Capital Management Company, L.P.
(b)	Address or principal business office or, if none, residence: 1 Financial Center, 24th Floor Boston, Massachusetts 02111
(c)	Citizenship: Westfield Capital Management Company, L.P. - MASSACHUSETTS
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 45245E109
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 2,737,381
(b)	Percent of class: 4.99 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Westfield Capital Management Company, L.P. - 2,604,711
	(ii) Shared power to vote or to direct the vote: Westfield Capital Management Company, L.P. - 0
	(iii) Sole power to dispose or to direct the disposition of: Westfield Capital Management Company, L.P. - 2,737,381
	(iv) Shared power to dispose or to direct the disposition of: Westfield Capital Management Company, L.P. - 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Westfield Capital Management Company, L.P.

Signature:	Brandi McMahon
Name/Title:	Vice President, Deputy Chief Compliance Officer
Date:	06/03/2026

FAQ

What stake does Westfield Capital report in IMAX (IMAX)?

Westfield Capital reports 2,737,381 shares beneficially owned, representing 4.99% of IMAX common stock. The filing also discloses 2,604,711 shares as sole voting power and documents sole dispositive power over the full 2,737,381 share position.

Does Westfield Capital have voting control over its IMAX shares?

Yes. The filing shows sole voting power for 2,604,711 shares, indicating Westfield can direct votes on most of its holdings. It reports 0 shared voting power and sole dispositive power for the full 2,737,381 share position.

When was the IMAX ownership update filed and signed?

The document lists a cover date of 05/31/2026 and the signature by Brandi McMahon is dated 06/03/2026. Those dates anchor the reported 2,737,381 share position and the voting/dispositive power values disclosed in this amendment.

Does the Schedule 13G/A indicate Westfield plans to sell or buy IMAX shares?

The filing provides ownership, voting, and dispositive power figures only; it does not state any intention to buy or sell. The document records current beneficial ownership of 2,737,381 shares but contains no language describing trading plans or transactions.

Why is the 4.99% figure significant on a Schedule 13G/A?

Reporting thresholds trigger different disclosure obligations. The filing records a 4.99% beneficial ownership level, which is at or below common 5% guidance; accordingly, the filer documents voting and dispositive powers while indicating ownership of 5 percent or less of the class.