WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC

Position in ADTN — ADTRAN Holdings, Inc.

CIK 1644956 CHICAGO, IL

Position in ADTN

as of Jun 30, 2026 · filed Aug 12, 2026 Compact

Position Value

$15,276,364

-$9,751,923 QoQ

Shares Held

1,099,019

-44.8% QoQ

Ownership

1.35%

of shares outstanding

% of Portfolio

0.05%

of 13F equity value

Holder Rank

#18

of 249 holders

Holding Since

Jun 2023

13 quarters on record

Voting authority Sole 62% Shared 0% None 38%

Technology · as of Jun 30, 2026

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC holds $195,112,302 across 6 Communication Equipment names. ADTN ranks #5 (7.8% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	AAOI	Applied Optoelectronics, Inc.	504,202	$74,702,568
2	CIEN	Ciena Corp	133,801	$65,637,418
3	BDC	Belden Inc.	178,144	$21,361,247
4	MSI	Motorola Solutions, Inc.	42,766	$17,760,292
5	ADTN	ADTRAN Holdings, Inc. This page	1,099,019	$15,276,364
6	HPE	Hewlett Packard Enterprise Co	8,300	$374,413

13 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$15,276,364	1,099,019	-44.8%	Shares	Sole	2026-08-12
2026-03-31	$25,028,287	1,989,530	-19.7%	Shares	Sole	2026-05-08
2025-12-31	$21,539,216	2,478,621	-9.4%	Shares	Sole	2026-02-09
2025-09-30	$25,667,713	2,736,430	-5.7%	Shares	Sole	2025-11-12
2025-06-30	$26,035,658	2,902,526	-7.5%	Shares	Sole	2025-07-29
2025-03-31	$27,372,978	3,139,103	-32.5%	Shares	Sole	2025-05-09
2024-12-31	$38,710,801	4,647,155	+2.5%	Shares	Sole	2025-02-10
2024-09-30	$26,875,762	4,532,169	+2.1%	Shares	Sole	2024-11-08
2024-06-30	$23,339,603	4,437,187	-0.4%	Shares	Sole	2024-08-08
2024-03-31	$24,241,004	4,456,067	+22.5%	Shares	Sole	2024-05-08
2023-12-31	$26,705,158	3,638,305	+51.2%	Shares	Sole	2024-02-09
2023-09-30	$19,800,054	2,405,839	+57.2%	Shares	Sole	2023-11-09
2023-06-30	$16,118,260	1,530,699	—	Shares	Sole	2023-08-11
No filing history on record for this holder in this stock.