[SCHEDULE 13G/A] Waystar Holding Corp. SEC Filing

Rhea-AI Filing Summary

Waystar Holding Corp. disclosure: Bain Capital-affiliated reporting persons BCPE Derby Investor, LP and BCPE Derby (DE) SPV, LP jointly report beneficial ownership. BCPE Derby holds 2,609,155 shares (~1.5%) and BCPE Derby SPV holds 15,445,894 shares (~8.9%), for a combined 18,055,049 shares representing ~10.3% of outstanding common stock based on 174,146,070 shares outstanding per the issuer's quarterly report. Neither reporting person has sole voting or dispositive power; voting and investment decisions are made by the partners of Bain Capital Investors, LLC. A Stockholders Agreement gives the reporting parties the right to nominate one director while they hold 5% or more; the Agreement requires supporting votes by other parties and the Reporting Persons expressly disclaim group membership.

Insights

Financial Analyst

Material 10.3% combined stake and an explicit director nomination right create a notable ownership and governance position.

The filing discloses that two Bain Capital-affiliated entities together beneficially own 18,055,049 Waystar shares (~10.3% of outstanding stock). The holdings are recorded as shared voting and dispositive power rather than sole control, and voting/investment choices are made by partners of Bain Capital Investors, LLC. The Stockholders Agreement giving a nomination right while holdings exceed 5% is a direct, legally documented governance lever that may affect board composition and oversight. For investors, the combination of a double-digit stake and formal nomination rights is a material corporate-governance development to monitor.

Corporate Governance Expert

Formal nomination right plus coordinated ownership implies tangible governance influence, though sole control is not asserted.

The document shows a coordinated ownership structure between BCPE Derby Investor and BCPE Derby (DE) SPV yielding an aggregate 10.3% stake and a contractual right to nominate one director while maintaining ≥5% ownership. The filing notes that the Agreement requires allied parties to vote for nominees and thus could amount to collective action, yet the Reporting Persons expressly disclaim being a group. Importantly, there is no sole voting or dispositive power reported—all authority is shared—so influence derives from agreement terms and combined shareholdings rather than unilateral voting control.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 3)

Waystar Holding Corp.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

946784105

(CUSIP Number)

06/30/2025

(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)

SCHEDULE 13G

CUSIP No. 946784105

1

Names of Reporting Persons

BCPE Derby Investor, LP

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 2,609,155.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,609,155.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,609,155.00

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)

1.5 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 946784105

1

Names of Reporting Persons

BCPE Derby (DE) SPV, LP

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 15,445,894.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 15,445,894.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

15,445,894.00

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)

8.9 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Waystar Holding Corp.
(b)	Address of issuer's principal executive offices: 1550 Digital Drive, #300, Lehi, Utah 84043
Item 2.
(a)	Name of person filing: This Schedule 13G is being filed jointly by BCPE Derby Investor, LP, a Delaware limited partnership ("BCPE Derby"), and BCPE Derby (DE) SPV, LP, a Delaware limtied partnership ("BCPE Derby SPV" and, together with BCPE Derby, the "Reporting Persons"). Bain Capital Investors, LLC ("BCI"), a Delaware limited liability company, is the manager of Bain Capital Partners XI, LP, a Cayman Islands exempted limited partnership ("Partners XI"), which is the general partner of Bain Capital Fund XI, LP, a Cayman Islands exempted limited partnership ("Fund XI"). Fund XI is the (i) sole member of BCPE Derby GP, LLC, a Delaware limited liability company ("BCPE Derby GP"), which is the general partner of BCPE Derby, and (ii) sole member of BCPE Derby (DE) SPV, LLC, a Delaware limtied liability company ("BCPE Derby SPV GP" and, together with the Reporting Persons, BCI, Partners XI, Fund XI and BCPE Derby GP, the "Bain Capital Entities"), which is the general partner of BCPE Derby SPV. As a result, BCI may be deemed to share voting and dispositive power with respect to the securities held by the Reportin Persons. Voting and investment decisions with respect to securities held by the Reporting Persons are made by the partners of BCI. The Reporting Persons have entered into a Joint Filing Agreement, dated August 14, 2025, pursuant to which the Reporting Persons have agreed to file this Schedule 13G jointly in accordance with the provisions of Rule 13d-1(k)(1) promulgated under the Act.
(b)	Address or principal business office or, if none, residence: The principal business address for each of the Bain Capital Entities is 200 Clarendon Street, Boston, Massachusetts 02116.
(c)	Citizenship: The Reporting Persons, BCI, BCPE Derby GP and BCPE Derby SPV GP are each organized under the laws of the State of Delaware. Partners XI and Fund XI are each organized under the laws of the Cayman Islands.
(d)	Title of class of securities: Common Stock, par value $0.01 per share
(e)	CUSIP No.: 946784105
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: As of the close of business on June 30, 2025, BCPE Derby held 2,609,155 shares of common stock, representing approximately 1.5% of the outstanding common stock, and BCPE Derby SPV held 15,445,894 shares of common stock, representing approximately 8.9% of the outstanding common stock. As a result of the foregoing and the relationships described in Item 2(a) of this Schedule 13G, the Reporting Persons may be deemed to collectively beneficially own an aggregate of 18,055,049 shares of common stock, representing approximately 10.3% of the outstanding common stock. The percentage of the outstanding shares of common stock held by the Reporting Persons is based on 174,146,070 shares of common stock issued and outstanding, as reported by the Issuer in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on July 30, 2025. The Reporting Persons and certain other stockholders are parties to a Stockholders Agreement (the "Agreement") with the Issuer, which was filed on a Form 8-K by the Issuer on June 12, 2024. The Agreement provides the Reporting Persons with the right to nominate one director to the Issuer's board of directors for so long as the Reporting Persons hold 5% or more of the then-outstanding common stock. The Agreement further requires that the Reporting Persons and other parties to the Agreement that hold similar nomination rights vote in favor of those nominated pursuant to the Agreement and, as such, may be deemed to constitute a group for purposes of Section 13(d) under the Securities Exchange Act of 1934, as amended. Notwithstanding the foregoing, the Reporting Persons expressly disclaim membership in such group and the filing of this Statement shall not be deemed an admission of such group membership or beneficial ownership of the securities held by the other parties to the Agreement.
(b)	Percent of class: See Item 4(a) hereof.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: See Item 4(a) hereof.
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: See Item 4(a) hereof.
Item 5.	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.
	If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group. See Item 4(a) hereof.
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.	Certifications:
	Not Applicable

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.

BCPE Derby Investor, LP

Signature:	/s/ David Humphrey
Name/Title:	David Humphrey, Partner of Bain Capital Investors, LLC
Date:	08/14/2025

BCPE Derby (DE) SPV, LP

Signature:	/s/ David Humphrey
Name/Title:	David Humphrey, Partner of Bain Capital Investors, LLC
Date:	08/14/2025