Adtran Holdings, Inc.: Release according to Article 40, Section 1 of the WpHG [the German Securities Trading Act] with the objective of Europe-wide distribution

Notification of Major Holdings

1. Details of issuer

Name:	Adtran Holdings, Inc.
Street:	901 Explorer Boulevard
Postal code:	35806
City:	Huntsville United States
Legal Entity Identifier (LEI):	549300VV36J86CRRWF77

2. Reason for notification

	Acquisition/disposal of shares with voting rights
X	Acquisition/disposal of instruments
	Change of breakdown of voting rights
	Other reason:

3. Details of person subject to the notification obligation

Legal entity: UBS Group AG City of registered office, country: Zurich, Switzerland

4. Names of shareholder(s)
holding directly 3% or more voting rights, if different from 3.

5. Date on which threshold was crossed or reached:

05 May 2026

6. Total positions

	% of voting rights attached to shares (total of 7.a.)	% of voting rights through instruments (total of 7.b.1 + 7.b.2)	Total of both in % (7.a. + 7.b.)	Total number of voting rights pursuant to Sec. 41 WpHG
New	1.78 %	6.01 %	7.78 %	80971042
Previous notification	1.89 %	3.99 %	5.88 %	/

7. Details on total positions
a. Voting rights attached to shares (Sec. 33, 34 WpHG)

ISIN	Absolute		In %
	Direct (Sec. 33 WpHG)	Indirect (Sec. 34 WpHG)	Direct (Sec. 33 WpHG)	Indirect (Sec. 34 WpHG)
US00486H1059	0	1439188	0 %	1.78 %
Total	1439188		1.78 %

b.1. Instruments according to Sec. 38 (1) no. 1 WpHG

Type of instrument	Expiration or maturity date	Exercise or conversion period	Voting rights absolute	Voting rights in %
Right of Use over Long Call Options	18/06/2026		5000	0.01 %
Rights of Use over Shares		At any time	968792	1.2 %
Right to Recall of Lent shares		At any time	1809893	2.24 %
		Total	2783685	3.44 %

b.2. Instruments according to Sec. 38 (1) no. 2 WpHG

Type of instrument	Expiration or maturity date	Exercise or conversion period	Cash or physical settlement	Voting rights absolute	Voting rights in %
Equity Swaps	11/11/2027 - 31/05/2028		Cash	331	0 %
Convertible Notes (US00486HAA32)	15/09/2030	19/09/2025 - 14/09/2030	Physical	1492793	1.84 %
Right of Use over Convertibles Notes		At any time	Physical	585518	0.72 %
			Total	2078642	2.57 %

8. Information in relation to the person subject to the notification obligation

	Person subject to the notification obligation is not controlled nor does it control any other undertaking(s) that directly or indirectly hold(s) an interest in the (underlying) issuer (1.).
X	Full chain of controlled undertakings starting with the ultimate controlling natural person or legal entity:

Name	% of voting rights (if at least 3% or more)	% of voting rights through instruments (if at least 5% or more)	Total of both (if at least 5% or more)
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Americas Holding LLC	%	%	%
UBS Americas Inc.	%	%	%
UBS Asset Management (Americas) LLC	%	%	%
-	%	%	%
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Asset Management AG	%	%	%
UBS Asset Management (Europe) S.A.	%	%	%
-	%	%	%
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Americas Holding LLC	%	%	%
UBS Americas Inc.	%	%	%
UBS Financial Services Inc.	%	%	%
-	%	%	%
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Asset Management AG	%	%	%
UBS Asset Management Switzerland AG	%	%	%
UBS Fund Management (Switzerland) AG	%	%	%
-	%	%	%
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Americas Holding LLC	%	%	%
UBS Americas Inc.	%	%	%
UBS Securities LLC	%	%	%
-	%	%	%
UBS Group AG	%	%	%
UBS AG	%	%	%
UBS Switzerland AG	%	%	%

9. In case of proxy voting according to Sec. 34 para. 3 WpHG
(only in case of attribution of voting rights in accordance with Sec. 34 para. 1 sent. 1 No. 6 WpHG)

Date of general meeting:
Holding total positions after general meeting (6.) after annual general meeting:

Proportion of voting rights	Proportion of instruments	Total of both
%	%	%

10. Other explanatory remarks:

Date

08 May 2026