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PRIMECAP decreased CIEN position by 75,600 shares

Mar 28, 2026Last updated Apr 16, 2026

This StonkWhisper whale intelligence report documents significant institutional position changes in $CIEN based on SEC 13F filings and block-level trading data. Quarterly 13F disclosures are required for institutional investment managers with at least $100 million in qualifying assets under management. These filings reveal long positions in U.S. equities held as of quarter end. Material changes in institutional positioning — particularly from concentrated funds with a history of high-conviction bets — are tracked by StonkWhisper as leading indicators of institutional thesis formation or exit.

PRIMECAP MANAGEMENT CO/CA/ AUM: $132.1B DECREASED

AUM: $132.1B · 319 holdings · Period: 2025-12-31

75,600 Share Change

511,600 Current Shares

$119.6B Current Value

0.09% Portfolio %

-12.9% Change %

Position Change Detail

Issuer CIENA CORP

Ticker CIEN

Shares 587,200 → 511,600 75,600

Value $85.5B → $119.6B

Portfolio Weight 0.09%

Change Type Decreased

Period of Report 2025-12-31

Other PRIMECAP Positions This Period

Ticker	Issuer	Change Type	Share Change	Value
WFC	WELLS FARGO CO NEW	Decreased	6,566,583	$779.2B
SONY	SONY GROUP CORP	Decreased	6,140,660	$1492.5B
NWL	NEWELL BRANDS INC	Decreased	5,309,046	$32.4B
OPTU	ALTICE USA INC	Exited	4,869,860	—
MU	MICRON TECHNOLOGY INC	Decreased	4,860,499	$7076.7B
CHV	CHEVRON CORP NEW	Decreased	4,037,474	$354.4B
NFLX	NETFLIX INC	Increased	+3,826,870	$377.2B
ELAN	ELANCO ANIMAL HEALTH INC	Decreased	3,744,068	$1045.8B
INTC	INTEL CORP	Decreased	3,273,242	$2809.3B
AZN	ASTRAZENECA PLC	Decreased	2,942,710	$3393.6B

Other Whales Moving CIEN This Period

Manager	Change Type	Share Change
Lone Pine	Exited	2,006,662
AQR Capital	Increased	+1,377,376
William Blair	Decreased	1,342,295
Arrowstreet	Increased	+1,092,980
State Street	Increased	+750,128
Point72	Decreased	453,622
Whale Rock	Decreased	444,317
Artisan Partners	Exited	434,292
Millennium	Increased	+348,516
American Century	Decreased	332,996

View all sentiment, news, and whale activity for CIEN (CIENA CORP).

Track PRIMECAP and other whale moves in real time on The Wire →

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Data sourced from SEC 13F institutional holdings filings. This page does not constitute financial advice. StonkWhisper presents public records — it does not verify or guarantee the accuracy of institutional filings. 13F filings are reported quarterly and may lag actual positions.

Last updated: April 16, 2026 at 06:01 UTC