CIENA CORP (CIEN) Stock Institutional Trading Activity


CIENA CORP (CIEN) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Renaissance Technologies LLC, Lone Pine Capital, First Eagle U.S. Value, Mairs & Power Growth Fund, and Sequoia Financial Advisors. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q4 2025Renaissance Technologies LLCSell-276,57432,600$7,624,162
Q3 2025Mairs & Power Growth FundSell-1,0003,000$437,010
Q3 2025Sequoia Financial AdvisorsBuy5133,956$576,271
Q3 2025First Eagle U.S. ValueSell-50,94967,400$9,818,158
Q3 2025Lone Pine CapitalBuy2,006,6622,006,662$292,310,454
Q2 2025Sequoia Financial AdvisorsBuy3,4433,443$280,020
Q2 2025Mairs & Power Growth FundBuy4,0004,000$325,320
Q2 2025First Eagle U.S. ValueBuy105,834118,349$9,625,324
Q1 2025Renaissance Technologies LLCBuy174,500309,174$18,683,385
Q1 2024Giverny CapitalSell-625,275661$32,686
Q4 2023Renaissance Technologies LLCBuy96,700134,674$6,062
Q4 2023Giverny CapitalSell-9,527625,936$28,173,379
Q3 2023Giverny CapitalSell-68,069635,463$30,031,981
Q2 2023First Eagle U.S. ValueBuy1,00012,515$531,763
Q2 2023Giverny CapitalBuy36,856703,532$29,893,075
Q1 2023First Eagle U.S. ValueBuy10,74511,515$604,768
Q1 2023Giverny CapitalSell-13,981666,676$35,013,824
Q4 2022Giverny CapitalSell-1,629680,657$34,700
Q4 2022First Eagle U.S. ValueBuy30770$39,255
Q3 2022First Eagle U.S. ValueBuy419740$30
Q3 2022Giverny CapitalBuy7,769682,286$27,585
Q2 2022First Eagle U.S. ValueBuy49321$15
Q2 2022Giverny CapitalBuy28,546674,517$30,825
Q1 2022First Eagle U.S. ValueBuy272272$16
Q1 2022Renaissance Technologies LLCSell-173,00037,974$2,302
Q1 2022Giverny CapitalBuy312,987645,971$39,165
Q4 2021Renaissance Technologies LLCSell-73,000210,974$16,239
Q4 2021Giverny CapitalBuy332,984332,984$25,630
Q1 2020Renaissance Technologies LLCSell-898,100283,974$11,305
Q4 2019Renaissance Technologies LLCBuy383,3001,182,074$50,463

Frequently asked questions about CIEN activity

  • Which institutional owners are buying CIEN?

    Institutional owners buying CIEN include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in CIEN activity?

    "Buy" means an investor increased their reported position in CIEN compared to the prior reporting period. This reflects growing exposure to CIENA CORP (CIEN) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in CIEN increasing?

    Institutional interest in CIEN can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.