# EDGAR Filing Document

**Accession Number:** 0001990354
**File Stem:** 0001193125-25-283241
**Filing Date:** 2025-11
**Character Count:** 12307
**Document Hash:** e26ff54234c01ef2384d4c94ff49a7b0
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-283241.hdr.sgml**: 20251114

**ACCESSION NUMBER**: 0001193125-25-283241

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251114

**DATE AS OF CHANGE**: 20251114

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Waystar Holding Corp.
- **CENTRAL INDEX KEY:** 0001990354
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-94694
- **FILM NUMBER:** 251487790

**BUSINESS ADDRESS:**
- **STREET 1:** 1550 DIGITAL DRIVE, #300
- **CITY:** LEHI
- **STATE:** UT
- **ZIP:** 84043
- **BUSINESS PHONE:** 844-492-9782

**MAIL ADDRESS:**
- **STREET 1:** 1550 DIGITAL DRIVE, #300
- **CITY:** LEHI
- **STATE:** UT
- **ZIP:** 84043
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BCPE Derby Investor, LP
- **CENTRAL INDEX KEY:** 0002025342

**ORGANIZATION NAME:**
- **EIN:** 874043559
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**BUSINESS ADDRESS:**
- **STREET 1:** 200 CLARENDON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 6175162000

**MAIL ADDRESS:**
- **STREET 1:** 200 CLARENDON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

### Attached PDF Documents

**Attachment 1:** `ck0000000000-ex99_a.pdf`

_No text found in this document._

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 4)**

**Issuer:** Waystar Holding Corp.

**Title of Class of Securities:** Common Stock, par value $0.01 per share

**CUSIP Number:** 946784105

**Date of Event Which Requires Filing of this Statement:** 09/30/2025

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

- [ ] Rule 13d-1(b)

- [ ] Rule 13d-1(c)

- [x] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>BCPE Derby Investor, LP | Names of Reporting Persons<br>BCPE Derby Investor, LP |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>1913839 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>1913839 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1913839 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>1913839 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>1.0% | Percent of Class Represented by Amount in Row (9)<br>1.0% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>BCPE Derby (DE) SPV, LP | Names of Reporting Persons<br>BCPE Derby (DE) SPV, LP |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>11329700 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>11329700 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>11329700 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>11329700 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>5.9% | Percent of Class Represented by Amount in Row (9)<br>5.9% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

**Item 1(a). Name of Issuer:**
Waystar Holding Corp.

**Item 1(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 November 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.

**Item 2(b). Address of Principal Business Office:**
The principal business address for each of the Bain Capital Entities is 200 Clarendon Street, Boston, Massachusetts 02116.

**Item 2(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.

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.01 per share

**Item 2(e). CUSIP Number:**
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 September 30, 2025, BCPE Derby held 1,913,839 shares of common stock, representing approximately 1.0% of the outstanding common stock, and BCPE Derby SPV held 11,329,700 shares of common stock, representing approximately 5.9% 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 13,243,539 shares of common stock, representing approximately 6.9% of the outstanding common stock.
The percentage of the outstanding shares of common stock held by the Reporting Persons is based on 191,316,583 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 October 29, 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 Five Percent or Less of a Class.**

[x] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

See Item 4(a) hereof.

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

—

### 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**

**Date:** 11/14/2025

**By:** /s/ David Humphrey

**Name & Title:** David Humphrey, Partner of Bain Capital Investors, LLC

**BCPE Derby (DE) SPV, LP**

**Date:** 11/14/2025

**By:** /s/ David Humphrey

**Name & Title:** David Humphrey, Partner of Bain Capital Investors, LLC