SEC 13F Intelligence

William Blair Investment Management, LLC / CIEN

William Blair Investment Management, LLC’s Ciena Corp Position

Does William Blair Investment Management, LLC own Ciena Corp (CIEN)? Yes — 398.6K shares worth $155M (+0.51% of its 13F portfolio) as of Q1 2026, down from 1.10M shares the prior filed quarter.

Position Value
$155M
Q1 2026
Shares
398.6K
% of Portfolio
+0.51%
Quarters Held
7
currently held

Position History CIEN

Reported value by quarter
Q4 ’18: $18MQ4 ’18Q1 ’19: $18MQ1 ’19Q1 ’25: $121MQ1 ’25Q2 ’25: $220MQ2 ’25Q3 ’25: $356MQ3 ’25Q4 ’25: $257MQ4 ’25Q1 ’26: $155MQ1 ’26filingsflow.com
QuarterSharesValue% of Portfolio
Q1 2026398.6K$155M+0.51%
Q4 20251.10M$257M+0.72%
Q3 20252.44M$356M+0.92%
Q2 20252.71M$220M+0.58%
Q1 20252.01M$121M+0.34%
Q1 2019472.5K$18M+0.07%
Q4 2018520.9K$18M+0.09%

Common-stock position only; options are excluded. Quarters where the fund filed no 13F or reported no position are absent. See William Blair Investment Management, LLC’s full portfolio or all institutional holders of CIEN.