Historical shareholding details of PRIMECAP Management Company holdings in CIENA Corp. (CIEN)

Monthly changes of PRIMECAP Management Company shareholding in CIENA Corp. over the previous months

Month	Name	Total no. shares held	Percent Holding
Month	Name	Total no. shares held	Percent Holding
Jun 30, 2025	Primecap Management Company	554,500	0.39%

Mar 31, 2025	Primecap Management Company	478,550	0.34%

Dec 31, 2024	Primecap Management Company	463,680	0.33%

Sep 30, 2024	Primecap Management Company	127,500	0.09%

Jun 30, 2024	Primecap Management Company	122,500	0.08%

Mar 31, 2024	Primecap Management Company	125,685	0.09%

Dec 31, 2023	Primecap Management Company	109,185	0.08%

Sep 30, 2023	Primecap Management Company	109,185	0.08%

Jun 30, 2023	Primecap Management Company	104,485	0.07%

Mar 31, 2023	Primecap Management Company	102,485	0.07%