西耶納公司
MX ˙ BMV ˙ US1717793095
SecurityMX:CIEN / Ciena Corporation
InstitutionRenaissance Technologies Llc
ManagerJames Simons
Latest Disclosed Ownership97,800 shares
Latest Disclosed Value $ 37,968,894
Renaissance Technologies Llc reports 200.00% increase in ownership of CIEN / Ciena Corporation

On May 14, 2026 - Renaissance Technologies Llc filed a 13F-HR form disclosing ownership of 97,800 shares of Ciena Corporation (MX:CIEN) valued at $37,968,894 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 32,600 shares of Ciena Corporation. This represents a change in shares of 200.00% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-14 2026-03-31 13F CIENA COM NEW 171779309 97,800 65,200 200.00 37,969 398.01 0.0594
2026-02-12 2025-12-31 13F CIENA COM NEW 171779309 32,600 32,600 7,624 0.0118
2025-08-13 2025-06-30 13F CIENA COM NEW 171779309 0 -309,174 -100.00 0 -100.00
2025-05-14 2025-03-31 13F CIENA COM NEW 171779309 309,174 309,174 18,683 0.0283
2024-05-13 2024-03-31 13F CIENA COM NEW 171779309 0 -134,674 -100.00 0 -100.00
2024-02-13 2023-12-31 13F CIENA COM NEW 171779309 134,674 134,674 6 0.0094
2022-08-12 2022-06-30 13F CIENA COM NEW 171779309 0 -37,974 -100.00 0 -100.00
2022-05-13 2022-03-31 13F CIENA COM NEW 171779309 37,974 -173,000 -82.00 2,302 -85.82 0.0027
2022-02-11 2021-12-31 13F CIENA COM NEW 171779309 210,974 210,974 16,239 0.0202
2020-08-13 2020-06-30 13F CIENA COM NEW 171779309 0 -283,974 -100.00 0 -100.00
2020-05-14 2020-03-31 13F CIENA COM NEW 171779309 283,974 -898,100 -75.98 11,305 -77.60 0.0110
2020-02-13 2019-12-31 13F CIENA COM NEW 171779309 1,182,074 383,300 47.99 50,463 61.04 0.0388
2019-11-13 2019-09-30 13F CIENA COM NEW 171779309 798,774 408,700 104.77 31,336 95.31 0.0265
2019-08-12 2019-06-30 13F CIENA COM NEW 171779309 390,074 -1,208,200 -75.59 16,044 -73.12 0.0141
2019-05-14 2019-03-31 13F CIENA COM NEW 171779309 1,598,274 1,318,400 471.07 59,680 528.81 0.0543
2019-02-12 2018-12-31 13F CIENA COM NEW 171779309 279,874 -952,321 -77.29 9,491 -75.34 0.0104
2018-11-13 2018-09-30 13F CIENA COM NEW 171779309 1,232,195 1,024,721 493.90 38,494 599.89 0.0396
2018-08-13 2018-06-30 13F/A-1 CIENA COM NEW 171779309 207,474 -1,254,600 -85.81 5,500 -85.48 0.0060
2018-08-13 2018-06-30 13F CIENA COM NEW 171779309 1,462,074 37,868
2018-05-14 2018-03-31 13F CIENA COM NEW 171779309 1,462,074 -454,300 -23.71 37,868 -5.59 0.0414
2018-02-13 2017-12-31 13F CIENA COM NEW 171779309 1,916,374 1,916,374 31.07 40,110 5.92 0.0442
2017-11-13 2017-09-30 13F CIENA COM NEW 171779309 0 -688,474 -100.00 0 -100.00
2017-08-11 2017-06-30 13F CIENA COM NEW 171779309 688,474 -1,850,500 -72.88 17,226 -71.26 0.0220
2017-05-12 2017-03-31 13F CIENA COM NEW 171779309 2,538,974 -1,493,300 -37.03 59,945 -39.10 0.0838
2017-02-13 2016-12-31 13F CIENA COM NEW 171779309 4,032,274 2,167,574 116.24 98,428 142.14 0.1557
2016-11-14 2016-09-30 13F CIENA COM NEW 171779309 1,864,700 -12,000 -0.64 40,650 15.52 0.0719
2016-08-12 2016-06-30 13F CIENA COM NEW 171779309 1,876,700 -66,474 -3.42 35,188 -4.79 0.0670
2016-05-13 2016-03-31 13F CIENA COM NEW 171779309 1,943,174 -55,200 -2.76 36,959 -10.61 0.0703
2016-02-11 2015-12-31 13F CIENA COM NEW 171779309 1,998,374 1,771,490 780.79 41,346 779.51 0.0901
2015-11-12 2015-09-30 13F CIENA COM NEW 171779309 226,884 -136,421 -37.55 4,701 -45.36 0.0112
2015-08-14 2015-06-30 13F CIENA COM NEW 171779309 363,305 315,105 653.74 8,603 824.06 0.0196
2015-05-13 2015-03-31 13F CIENA COM NEW 171779309 48,200 30,695 175.35 931 173.82 0.0020
2015-02-13 2014-12-31 13F CIENA COM NEW 171779309 17,505 17,505 -63.68 340 -63.48 0.0008
2014-02-14 2013-12-31 13F CIENA COM NEW 171779309 0 -1,668,505 -100.00 0 -100.00
2013-11-13 2013-09-30 13F CIENA COM NEW 171779309 1,668,505 537,100 47.47 41,728 89.82 0.1012
2013-08-12 2013-06-30 13F CIENA COM NEW 171779309 1,131,405 1,131,405 21,983 0.0576
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.