[SCHEDULE 13G/A] GeneDx Holdings Corp. SEC Filing

Rhea-AI Filing Summary

Summit Partners and affiliated entities reported beneficial ownership of 867,265 shares of GeneDx Holdings Corp. Class A common stock, representing 3.04% of the outstanding shares based on 28,553,204 common shares used for the calculation. The holdings are aggregated across several funds and accounts managed by Summit Partners Public Asset Management (SPPAM), with Summit Partners, L.P. serving as the managing member.

The filing shows the group has 0 sole voting power, 771,333 shares subject to shared voting power and 867,265 shares subject to shared dispositive power. SPPAM is identified as the investment manager for the funds holding the positions. The reporting persons state the securities were not acquired to influence control and the filing is made under a joint filing agreement with powers of attorney for certain signatories.

Positive

• Institutional disclosure of a 3.04% stake (867,265 shares) provides transparency into major holder positions
• Clear delineation of voting and dispositive power showing shared control rather than sole control

Negative

• None.

Insights

Financial Analyst

TL;DR: Institutional disclosure of a modest 3.04% stake across Summit-managed funds; passive reporting with shared control, not an activism signal.

The filing documents an aggregated beneficial position of 867,265 shares (3.04%) held by Summit-affiliated funds and accounts. Key metrics: 771,333 shares carry shared voting power and there is 0 sole voting or dispositive power. The investor type is an investment adviser/pooled funds structure, and the group certifies the holdings are not intended to change or influence control. From a market-impact perspective, a sub-5% passive disclosure is routine and unlikely to materially shift governance or strategy, though it signals Summit's exposure to the issuer.

Corporate Governance Expert

TL;DR: Governance implication is limited: shared voting power but no sole control; joint filing and certifications indicate compliance and non-control intent.

The report clarifies that voting authority over 771,333 shares is shared among the reporting persons and that dispositive authority is likewise shared for 867,265 shares. The absence of sole voting power and the explicit certification that the positions were not acquired to influence control reduce the likelihood of immediate governance actions. The joint filing agreement and referenced powers of attorney ensure consolidated disclosure but do not imply a coordinated governance campaign.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

GENEDX HOLDINGS CORP.

(Name of Issuer)

Class A common stock, par value $0.0001 per share

(Title of Class of Securities)

81663L200

(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. 81663L200

1

Names of Reporting Persons

Summit Partners Public Asset Management, LLC

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 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 867,265.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

867,265.00

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)

3.04 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners, 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 771,333.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

771,333.00

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)

2.7 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Concentrated Growth L/S Master Fund, 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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 103,992.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 103,992.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

103,992.00

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)

0.36 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Technology L/S Master Fund, 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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 67,546.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 67,546.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

67,546.00

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)

.24 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Sustainable Opportunities L/S Fund Limited

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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 235,761.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 235,761.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

235,761.00

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)

.83 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Sustainable Opportunities L/S QP Fund, 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 353,762.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 353,762.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

353,762.00

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)

1.24 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Sustainable Opportunities L/S Fund, 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 10,272.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 10,272.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,272.00

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)

.04 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Alydar GP, 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 535,572.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 535,572.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

535,572.00

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)

1.88 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Summit Partners Alydar GP, LLC

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 535,572.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 535,572.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

535,572.00

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)

1.88 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Philip Furse

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 867,265.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

867,265.00

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)

3.04 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Timothy Albright

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 867,265.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

867,265.00

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)

3.04 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Robert MacAulay

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 867,265.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

867,265.00

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)

3.04 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP No. 81663L200

1

Names of Reporting Persons

Matthew Curtis

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,333.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 867,265.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

867,265.00

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)

3.04 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: GENEDX HOLDINGS CORP.
(b)	Address of issuer's principal executive offices: 333 Ludlow Street, North Tower, 6th Floor, Stamford, CT, 06902
Item 2.
(a)	Name of person filing: The names of the persons filing this report (each a "Reporting Person" and collectively, the "Reporting Persons") are: (i) Summit Partners Public Asset Management, LLC ("SPPAM"), (ii) Summit Partners, L.P. ("SP"), (iii) Summit Partners Concentrated Growth L/S Master Fund, L.P. ("Summit Concentrated Growth"), (iv) Summit Partners Technology L/S Master Fund, L.P. ("Summit Technology"), (v) Summit Partners Sustainable Opportunities L/S Fund Limited ("SPSO Limited"), (vi) Summit Partners Sustainable Opportunities L/S QP Fund, L.P. ("SPSO QP"), (vii) Summit Partners Sustainable Opportunities L/S Fund, L.P. ("SPSO LP"), (viii) Summit Partners Alydar GP, L.P. ("Fund GP"), (ix) Summit Partners Alydar GP, LLC ("GP"), (x) Philip Furse, (xi) Timothy Albright, (xii) Robert MacAulay and (xiii) Matthew Curtis. The Reporting Persons have entered into a Joint Filing Agreement, dated February 12, 2025, a copy of which is incorporated by reference as Exhibit A to this statement, pursuant to which the Reporting Persons agreed to file this Schedule 13G and any amendments hereto jointly in accordance with the provisions of Rule 13d-1(k)(1) under the Act.
(b)	Address or principal business office or, if none, residence: The address of the principal business office or registered office, as applicable, of SPPAM, SP, SPSO QP, SPSO LP, Fund GP, GP, Philip Furse, Timothy Albright, Robert MacAulay and Matthew Curtis is 222 Berkeley Street, 18th Floor, Boston, MA 02116. The registered office address of Summit Concentrated Growth, Summit Technology and SPSO Limited is c/o Walkers Corporate Limited, 190 Elgin Avenue, George Town, Grand Cayman KY1-9008, Cayman Islands.
(c)	Citizenship: SPPAM, SP, SPSO QP, SPSO LP, Fund GP, and GP are organized under the laws of the State of Delaware. Philip Furse, Timothy Albright and Robert MacAulay are citizens of the United States. Summit Concentrated Growth and Summit Technology are each a Cayman Islands limited partnership. SPSO Limited is a Cayman Islands exempted company.
(d)	Title of class of securities: Class A common stock, par value $0.0001 per share
(e)	CUSIP No.: 81663L200
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: 867,265
(b)	Percent of class: 3.04%
(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: 771,333
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 867,265
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 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.

Summit Partners Public Asset Management, LLC

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Concentrated Growth L/S Master Fund, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Technology L/S Master Fund, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Sustainable Opportunities L/S Fund Limited

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Sustainable Opportunities L/S QP Fund, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Sustainable Opportunities L/S Fund, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Alydar GP, L.P.

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Summit Partners Alydar GP, LLC

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, Authorized Person
Date:	08/14/2025

Philip Furse

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, POA for Philip Furse
Date:	08/14/2025

Timothy Albright

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, POA for Timothy Albright
Date:	08/14/2025

Robert MacAulay

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, POA for Robert MacAulay
Date:	08/14/2025

Matthew Curtis

Signature:	Adam H. Hennessey
Name/Title:	Adam H. Hennessey, POA for Matthew Curtis
Date:	08/14/2025

Exhibit Information

Item 4: The information required by Item 4 with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of each cover page to this Schedule 13G. The ownership percentages are calculated based on 28,553,204 outstanding shares of Common Stock, as of April 23, 2025, as reported in the issuer's Quarterly Report on Form 10-Q filed on April 30, 2025. SPPAM is the investment manager with respect to shares of Common Stock and call options to purchase shares of Common Stock ("Call Options") directly held by Summit Concentrated Growth, SPSO QP, SPSO LP, SPSO Limited and Summit Technology (collectively the "Funds") and a separately managed account. SP is the Managing Member of SPPAM. Summit Concentrated Growth, Summit Technology, and a separately managed account each directly hold shares of Common Stock. SPSO Limited, SPSO QP and SPSO LP each directly holds shares of Common Stock and Call Options. Fund GP is the general partner of Summit Concentrated Growth, SPSO QP, SPSO LP and Summit Technology. GP is the general partner of Fund GP. Philip Furse is the Chief Investment Officer of SPPAM and a Portfolio Manager of SPPAM, with respect to the shares of Common Stock and Call Options directly held by the Funds and the separately managed account of SPPAM. Timothy Albright is a Portfolio Manager of SPPAM with respect to the shares of Common Stock and Call Options directly held by the Funds and the separately managed account of SPPAM. Robert MacAulay is the Chief Risk Officer of SPPAM with respect to the shares of Common Stock and Call Options directly held by the Funds and the separately managed account of SPPAM. Matthew Curtis is a Portfolio Manager of SPPAM with respect to the shares of Common Stock and Call Options directly held by the Funds and the separately managed account of SPPAM. Accordingly, each of the Reporting Persons may be deemed the beneficial owner of the reported securities but the filing of this statement shall not be construed as an admission that any of the Reporting Persons is, for the purpose of 13(d) or 13(g) of the Act, the beneficial owner of any securities covered by this statement. Please note that the Reporting Persons do not have any voting control over any of the securities held by the separately managed account referenced herein. EXHIBIT A JOINT FILING AGREEMENT This will confirm the agreement by and among the undersigned that the Schedule 13G filed with the Securities and Exchange Commission on or about the date hereof with respect to the beneficial ownership by the undersigned of the Common Stock (this "Agreement"), is being filed, and all amendments thereto will be filed, on behalf of each of the persons and entities named below that is named as a reporting person in such filing in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Joint Filing Agreement dated August 14, 2025, among Summit Partners Public Asset Management, LLC, Summit Partners, L.P., Summit Partners Concentrated Growth L/S Master Fund, L.P., Summit Partners Technology L/S Master Fund, L.P., Summit Partners Sustainable Opportunities L/S Fund Limited, Summit Partners Sustainable Opportunities L/S QP Fund, L.P., Summit Partners Sustainable Opportunities L/S Fund, L.P., Summit Partners Alydar GP, L.P., Summit Partners Alydar GP, LLC, Philip Furse, Timothy Albright, Robert MacAulay and Matthew Curtis. Dated: August 14, 2025 Summit Partners Public Asset Management, LLC Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Concentrated Growth L/S Master Fund, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Technology L/S Master Fund, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Sustainable Opportunities L/S Fund Limited Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Sustainable Opportunities L/S QP Fund, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Sustainable Opportunities L/S Fund, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Alydar GP, L.P. Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Summit Partners Alydar GP, LLC Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, Authorized Person Philip Furse Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, POA for Philip Furse Timothy Albright Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, POA for Timothy Albright Robert MacAulay Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, POA for Robert MacAulay Matthew Curtis Signature: /s/ Adam H. Hennessey Name/Title: Adam H. Hennessey, POA for Matthew Curtis EXHIBIT B POWERS OF ATTORNEY Powers of Attorney, dated as of January 31, 2024, (incorporated herein by reference to Exhibit B to that certain Schedule 13G filed on January 31, 2024, with the Securities and Exchange Commission in connection with securities of Klaviyo, Inc.).

FAQ

How many GeneDx (WGS) shares does Summit Partners report owning?

The filing reports beneficial ownership of 867,265 shares of GeneDx Class A common stock.

What percentage of GeneDx (WGS) does that stake represent?

The reported position represents 3.04% of the outstanding Class A common stock (calculated on 28,553,204 shares).

How much voting power does Summit Partners have over these WGS shares?

The group reports 0 shares with sole voting power and 771,333 shares with shared voting power.

Do the reporting persons claim intent to influence control of GeneDx (WGS)?

No; the certification states the securities were not acquired and are not held to change or influence control.

Which Summit entities are identified as holding or managing the WGS shares?

The filing names SPPAM as the investment manager, Summit Partners, L.P. as managing member, and multiple Summit funds and related entities as holders.

On what basis was the ownership percentage calculated?

The percentage is calculated using 28,553,204 outstanding shares of common stock, as disclosed in the issuer's quarterly report referenced in the filing.