Question 1

How many shares of CIEN does WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC own?

Accepted Answer

As of 2026-Q2, WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC holds 133,801 shares of CIEN (CIENA CORP).

Question 2

What is WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's CIEN position worth?

Accepted Answer

As of 2026-Q2, WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's CIEN position is worth $65.6M.

Question 3

Is WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC buying or selling CIEN?

Accepted Answer

In 2026-Q2, WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC decreased their CIEN position (-66.4% change in shares).

Question 4

When did WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC first buy CIEN?

Accepted Answer

Based on available 13F filings, WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC first reported a position in CIEN in 2025-Q1. They have held the position across 9 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	133,801	-66.4%	$65.6M	0.2%	$490.56	0
2026-Q1	Decreased	398,579	-63.7%	$154.7M	0.5%	$388.23	0
2025-Q4	Decreased	1.1M	-55.0%	$256.9M	0.7%	$233.87	0
2025-Q3	Decreased	2.4M	-9.9%	$355.6M	0.9%	$145.67	0
2025-Q2	Increased	2.7M	+35.0%	$220.3M	0.6%	$81.33	56
2025-Q1	New	2M	—	$121.2M	0.3%	$60.43	50