Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
1,045 institutional managers reported holding CIEN for the quarter ended Mar 31, 2026. Together they hold about 85% of shares outstanding; the top 10 hold 52%. 299 opened new positions; 92 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| FMR (Fidelity) | 21.21M | 14.55% | $8.23B | unchanged | ≤2013 |
| Vanguard Group | 17.98M | 12.33% | $6.98B | added +24.9% | ≤2013 |
| BlackRock | 13.37M | 9.17% | $5.19B | trimmed -19.8% | ≤2013 |
| State Street | 6.31M | 4.33% | $2.45B | added +23.6% | ≤2013 |
| T. Rowe Price | 5.24M | 3.60% | $2.04B | added +29.4% | ≤2013 |
| Geode Capital | 4.07M | 2.79% | $1.58B | added +51.3% | ≤2013 |
| Capital Research Global Investors | 2.75M | 1.89% | $1.07B | opened | 2026 Q1 |
| Bank OF America CORP /DE/ | 1.95M | 1.34% | $758.9M | trimmed -9.7% | ≤2013 |
| Capital Group (American Funds) | 1.72M | 1.18% | $669.6M | trimmed -7.7% | 2025 Q1 |
| Jericho Capital Asset Management L.p. (focused) | 1.66M | 1.14% | $643.0M | unchanged | 2025 Q2 |
| Morgan Stanley | 1.56M | 1.07% | $606.3M | added +12.7% | ≤2013 |
| Invesco | 1.53M | 1.05% | $594.1M | added +0.8% | ≤2013 |
| UBS | 1.50M | 1.03% | $582.4M | added +21.2% | ≤2013 |
| BNP Paribas Financial Markets | 1.45M | 0.99% | $561.2M | trimmed -29% | ≤2013 |
| Arrowstreet Capital | 1.39M | 0.95% | $539.1M | trimmed -37.9% | 2023 Q4 |
| Charles Schwab Investment Management | 1.27M | 0.87% | $493.9M | added +36% | ≤2013 |
| Voya Investment Management LLC | 1.21M | 0.83% | $467.9M | added +27.3% | ≤2013 |
| Northern Trust | 1.19M | 0.81% | $461.0M | trimmed -2.4% | ≤2013 |
| Dimensional Fund Advisors | 1.15M | 0.79% | $444.9M | trimmed -18% | ≤2013 |
| AQR Capital | 977.1k | 0.67% | $379.3M | trimmed -30.8% | 2017 Q2 |
| BNY Mellon | 926.9k | 0.64% | $359.8M | trimmed -17.1% | ≤2013 |
| Nuveen | 844.2k | 0.58% | $327.7M | trimmed -6% | 2019 Q2 |
| Lone Pine Capital (focused) | 809.5k | 0.56% | $314.3M | opened | 2025 Q3 |
| Polar Capital Holdings PLC | 798.4k | 0.55% | $310.0M | trimmed -38.1% | 2024 Q1 |
| Goldman Sachs | 773.3k | 0.53% | $300.2M | added +73.6% | ≤2013 |
| Atreides Management, LP | 676.8k | 0.46% | $262.8M | trimmed -52.6% | 2023 Q3 |
| Legal & General Group PLC | 648.4k | 0.45% | $251.7M | added +27% | 2014 Q3 |
| MFS Investment Management | 582.7k | 0.40% | $226.2M | trimmed -4.1% | 2025 Q3 |
| Point72 | 544.7k | 0.37% | $211.5M | added +15.7% | 2022 Q3 |
| American Century Companies INC | 535.8k | 0.37% | $208.0M | added +112% | ≤2013 |
| Deutsche Bank AG\ | 527.9k | 0.36% | $204.9M | trimmed -10.6% | ≤2013 |
| AllianceBernstein | 527.4k | 0.36% | $204.8M | added +47.5% | ≤2013 |
| PRIMECAP Management | 438.1k | 0.30% | $170.1M | trimmed -14.4% | 2020 Q2 |
| First Trust Advisors LP | 436.9k | 0.30% | $169.6M | trimmed -14.7% | 2016 Q1 |
| Amundi | 431.2k | 0.30% | $167.4M | trimmed -10.8% | 2018 Q1 |
| T. Rowe Price Investment Management, INC. | 418.5k | 0.29% | $162.5M | added +653742.2% | 2025 Q3 |
| Swiss National Bank | 413.3k | 0.28% | $160.5M | added +7% | ≤2013 |
| William Blair Investment Management, LLC | 398.6k | 0.27% | $154.7M | trimmed -63.7% | 2025 Q1 |
| Schroder Investment Management Group | 394.1k | 0.27% | $153.0M | trimmed -34.4% | 2013 Q4 |
| Mitsubishi UFJ Asset Management CO., LTD. | 382.3k | 0.26% | $148.4M | added +92.3% | 2023 Q3 |
| Assenagon Asset Management S.a. | 364.5k | 0.25% | $141.5M | trimmed -29.1% | 2019 Q4 |
| Wells Fargo & COMPANY/MN | 352.4k | 0.24% | $136.8M | added +21.6% | ≤2013 |
| Acadian Asset Management | 330.1k | 0.23% | $128.2M | added +16.7% | 2018 Q3 |
| Prudential Financial INC | 325.8k | 0.22% | $126.5M | trimmed -33.4% | ≤2013 |
| Balyasny Asset Management | 323.4k | 0.22% | $125.6M | trimmed -26.5% | 2021 Q3 |
| Sumitomo Mitsui Trust Group, INC. | 321.8k | 0.22% | $124.9M | added +10.7% | 2025 Q3 |
| Anatole Investment Management LTD (focused) | 313.4k | 0.21% | $121.7M | trimmed -37.5% | 2025 Q3 |
| Raymond James Financial INC | 304.8k | 0.21% | $118.3M | trimmed -14.6% | 2016 Q1 |
| Barrow Hanley Mewhinney & Strauss LLC | 301.6k | 0.21% | $117.1M | trimmed -36.5% | 2018 Q2 |
| National Pension Service | 298.5k | 0.20% | $115.9M | added +40.5% | 2025 Q4 |
Largest 50 of 1,045 shown; the full ranked, searchable register is at boothcheck.com/holders/CIEN. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.