UBS Group AG, Zurich, Switzerland

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:

09 Jun 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	1.9 %	5.39 %	7.28 %	81421186
Previous notification	1.69 %	4.78 %	6.47 %	/

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	1543104	0 %	1.9 %
Total	1543104		1.9 %

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 %
Rights of Use over Shares		At any time	86617	0.11 %
Right to Recall of Lent shares		At any time	1934032	2.38 %
Right of Use over Long Call Options		At any time	7200	0.01 %
		Total	2027849	2.49 %

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	325	0 %
Convertible Notes (US00486HAA32)	15/09/2030	19/09/2025 - 14/09/2030	Physical	2010852	2.47 %
Right of Use over Convertible Notes		At any time	Physical	345546	0.42 %
			Total	2356723	2.89 %

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

10 Jun 2026