Question 1

How many shares of CIEN does Capital World Investors own?

Accepted Answer

As of 2026-Q2, Capital World Investors holds 1.8M shares of CIEN (CIENA CORP).

Question 2

What is Capital World Investors's CIEN position worth?

Accepted Answer

As of 2026-Q2, Capital World Investors's CIEN position is worth $861.2M.

Question 3

Is Capital World Investors buying or selling CIEN?

Accepted Answer

In 2026-Q2, Capital World Investors increased their CIEN position (+1.8% change in shares).

Question 4

When did Capital World Investors first buy CIEN?

Accepted Answer

Based on available 13F filings, Capital World Investors first reported a position in CIEN in 2025-Q1. They have held the position across 16 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Increased	1.8M	+1.8%	$861.2M	0.1%	$490.56	39
2026-Q1	Decreased	1.7M	-7.7%	$669.6M	0.1%	$388.23	0
2025-Q4	Increased	1.9M	+1.7%	$437.1M	0.1%	$233.87	32
2025-Q3	Increased	1.8M	+7.7%	$267.6M	0.0%	$145.67	33
2025-Q2	Decreased	1.7M	-7.9%	$138.8M	0.0%	$81.33	0
2025-Q1	New	1.9M	—	$112M	0.0%	$60.43	42