Century Aluminum Company
DE ˙ DB ˙ US1564311082
56,08 € ↓ -1,98 (-3,41%)
2026-05-29
AKTIENPREIS
SecurityDE:EY3 / Century Aluminum Company
InstitutionGroup One Trading, L.p.
Latest Disclosed Ownership683 shares
Latest Disclosed Value $ 26,760
Group One Trading, L.p. ownership in EY3 / Century Aluminum Company

On February 11, 2026 - Group One Trading, L.p. filed a 13F-HR form disclosing ownership of 683 shares of Century Aluminum Company (DE:EY3) valued at $22,409 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 12, 2025 disclosing 32,275 shares of Century Aluminum Company. This represents a change in shares of -97.88% during the quarter. The current value of the position is $38,303 USD.

Group One Trading, L.p. has a history of taking positions in derivatives of the underlying security (EY3) in the form of stock options. The firm currently holds call options representing 106,200 of underlying shares valued at $4,160,916 USD and put options representing 42,800 of underlying shares valued at $1,676,904 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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.

Upgrade to unlock premium data and export to Excel .

Institutional Put/Call Ratios
(Premium Subscription Required)

In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

DE:EY3 / Century Aluminum Company Historical Put/Call Ratio
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)
2026-02-11 2025-12-31 13F CENTURY ALUM COM 156431108 683 -31,592 -97.88 27 -97.25 0.0000
2025-11-12 2025-09-30 13F CENTURY ALUM COM 156431108 32,275 32,275 948 0.0017
2024-05-10 2024-03-31 13F CENTURY ALUM COM 156431108 0 -90,646 -100.00 0 -100.00
2024-02-14 2023-12-31 13F CENTURY ALUM COM 156431108 90,646 52,624 138.40 1,100 302.93 0.0029
2023-11-09 2023-09-30 13F CENTURY ALUM COM 156431108 38,022 38,022 273 0.0009
2023-08-09 2023-06-30 13F CENTURY ALUM COM 156431108 0 -17,609 -100.00 0 -100.00
2023-05-12 2023-03-31 13F CENTURY ALUM COM 156431108 17,609 -120,887 -87.29 176 -84.45 0.0006
2023-02-09 2022-12-31 13F CENTURY ALUM COM 156431108 138,496 64,260 86.56 1,133 188.78 0.0026
2022-11-09 2022-09-30 13F CENTURY ALUM COM 156431108 74,236 -55,191 -42.64 392 -58.91 0.0008
2022-08-11 2022-06-30 13F CENTURY ALUM COM 156431108 129,427 25,297 24.29 954 -65.18 0.0015
2022-05-12 2022-03-31 13F CENTURY ALUM COM 156431108 104,130 93,881 916.00 2,740 1,511.76 0.0027
2022-02-11 2021-12-31 13F CENTURY ALUM COM 156431108 10,249 -39,535 -79.41 170 -74.63 0.0001
2021-11-12 2021-09-30 13F CENTURY ALUM COM 156431108 49,784 36,552 276.24 670 291.81 0.0007
2021-08-10 2021-06-30 13F CENTURY ALUM COM 156431108 13,232 -26,377 -66.59 171 -75.54 0.0002
2021-05-12 2021-03-31 13F CENTURY ALUM COM 156431108 39,609 39,609 699 0.0010
2019-05-14 2019-03-31 13F/A-1 CENTURY ALUM COM 156431108 0 -22,378 -100.00 0 -100.00
2019-02-05 2018-12-31 13F CENTURY ALUM COM 156431108 22,378 22,378 164 0.0014
2018-08-13 2018-06-30 13F CENTURY ALUM COM 156431108 0 -2,431 -100.00 0 -100.00
2018-05-16 2018-03-31 13F/A-1 CENTURY ALUM COM 156431108 2,431 971 66.51 40 37.93 0.0004
2018-05-10 2018-03-31 13F CENTURY ALUM COM 156431108 2,431 971 40
2018-02-09 2017-12-31 13F CENTURY ALUM COM 156431108 1,460 -2,337 -61.55 29 -53.97 0.0002
2017-11-15 2017-09-30 13F CENTURY ALUM COM 156431108 3,797 -18,778 -83.18 63 -82.10 0.0006
2017-08-14 2017-06-30 13F CENTURY ALUM COM 156431108 22,575 18,143 409.36 352 528.57 0.0037
2017-05-10 2017-03-31 13F CENTURY ALUM COM 156431108 4,432 4,432 56 0.0007
2016-05-12 2016-03-31 13F CENTURY ALUM COM 156431108 0 -5,330 -100.00 0 -100.00
2016-02-11 2015-12-31 13F CENTURY ALUM COM 156431108 5,330 -3,184 -37.40 24 -38.46 0.0003
2015-11-20 2015-09-30 13F/A-1 CENTURY ALUM COM 156431108 8,514 -3,271 -27.76 39 -68.29 0.0005
2015-11-06 2015-09-30 13F CENTURY ALUM COM 156431108 8,514 39
2015-08-11 2015-06-30 13F CENTURY ALUM COM 156431108 11,785 10,956 1,321.59 123 1,018.18 0.0017
2015-05-14 2015-03-31 13F CENTURY ALUM COM 156431108 829 829 11 0.0002
2015-02-11 2014-12-31 13F CENTURY ALUM COM 156431108 0 -16,377 -100.00 0 -100.00
2014-10-31 2014-09-30 13F CENTURY ALUM COM 156431108 16,377 16,377 425 0.0065
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-11 2025-12-31 13F CENTURY ALUM COM Call 106,200 44.69 4,161 93.04 n/a n/a n/a
2025-11-12 2025-09-30 13F CENTURY ALUM COM Call 73,400 -31.34 2,155 11.89 n/a n/a n/a
2025-08-14 2025-06-30 13F CENTURY ALUM COM Call 106,900 33.79 1,926 29.96 n/a n/a n/a
2025-05-14 2025-03-31 13F CENTURY ALUM COM Call 79,900 -17.80 1,483 -16.27 n/a n/a n/a
2025-05-14 2024-12-31 13F/A CENTURY ALUM COM Call 97,200 6.81 1,771 19.92 n/a n/a n/a
2025-02-14 2024-12-31 13F CENTURY ALUM COM Call 97,200 1,771 n/a n/a n/a
2024-11-14 2024-09-30 13F CENTURY ALUM COM Call 91,000 0.44 1,477 -2.70 n/a n/a n/a
2024-08-14 2024-06-30 13F CENTURY ALUM COM Call 90,600 -1.20 1,518 7.51 n/a n/a n/a
2024-05-10 2024-03-31 13F CENTURY ALUM COM Call 91,700 -24.84 1,411 -4.73 n/a n/a n/a
2024-02-14 2023-12-31 13F CENTURY ALUM COM Call 122,000 -6.94 1,481 57.22 n/a n/a n/a
2023-11-09 2023-09-30 13F CENTURY ALUM COM Call 131,100 104.52 943 68.82 n/a n/a n/a
2023-08-09 2023-06-30 13F CENTURY ALUM COM Call 64,100 133.94 559 103.65 n/a n/a n/a
2023-05-12 2023-03-31 13F CENTURY ALUM COM Call 27,400 37.69 274 69.14 n/a n/a n/a
2023-02-09 2022-12-31 13F CENTURY ALUM COM Call 19,900 70.09 163 161.29 n/a n/a n/a
2022-11-09 2022-09-30 13F CENTURY ALUM COM Call 11,700 -94.99 62 -96.40 n/a n/a n/a
2022-08-11 2022-06-30 13F CENTURY ALUM COM Call 233,400 -14.51 1,720 -76.05 n/a n/a n/a
2022-05-12 2022-03-31 13F CENTURY ALUM COM Call 273,000 1,782.76 7,183 2,892.92 n/a n/a n/a
2022-02-11 2021-12-31 13F CENTURY ALUM COM Call 14,500 -96.16 240 -95.27 n/a n/a n/a
2021-11-12 2021-09-30 13F CENTURY ALUM COM Call 377,400 540.75 5,076 568.77 n/a n/a n/a
2021-08-10 2021-06-30 13F CENTURY ALUM COM Call 58,900 261.35 759 163.54 n/a n/a n/a
2021-05-12 2021-03-31 13F CENTURY ALUM COM Call 16,300 1,258.33 288 2,115.38 n/a n/a n/a
2021-02-10 2020-12-31 13F CENTURY ALUM COM Call 1,200 0.00 13 44.44 n/a n/a n/a
2020-11-12 2020-09-30 13F CENTURY ALUM COM Call 1,200 100.00 9 125.00 n/a n/a n/a
2020-08-13 2020-06-30 13F CENTURY ALUM COM Call 600 -87.50 4 -76.47 n/a n/a n/a
2020-05-13 2020-03-31 13F CENTURY ALUM COM Call 4,800 1,100.00 17 466.67 n/a n/a n/a
2020-02-10 2019-12-31 13F CENTURY ALUM COM Call 400 300.00 3 200.00 n/a n/a n/a
2019-11-12 2019-09-30 13F CENTURY ALUM COM Call 100 1 n/a n/a n/a
2019-05-14 2019-03-31 13F/A CENTURY ALUM COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-02-05 2018-12-31 13F CENTURY ALUM COM Call 29,300 -2.01 214 -40.22 n/a n/a n/a
2018-11-08 2018-09-30 13F CENTURY ALUM COM Call 29,900 -37.45 358 -52.46 n/a n/a n/a
2018-08-13 2018-06-30 13F CENTURY ALUM COM Call 47,800 856.00 753 807.23 n/a n/a n/a
2018-05-16 2018-03-31 13F/A CENTURY ALUM COM Call 5,000 2.04 83 -13.54 n/a n/a n/a
2018-05-10 2018-03-31 13F CENTURY ALUM COM Call 5,000 83 n/a n/a n/a
2018-02-09 2017-12-31 13F CENTURY ALUM COM Call 4,900 96 n/a n/a n/a
2017-11-14 2017-09-30 13F CENTURY ALUM COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-08-14 2017-06-30 13F CENTURY ALUM COM Call 10,900 22.47 170 50.44 n/a n/a n/a
2017-05-10 2017-03-31 13F CENTURY ALUM COM Call 8,900 -69.93 113 -55.34 n/a n/a n/a
2017-02-15 2016-12-31 13F CENTURY ALUM COM Call 29,600 -52.10 253 -41.16 n/a n/a n/a
2016-11-14 2016-09-30 13F CENTURY ALUM COM Call 61,800 49.28 430 64.12 n/a n/a n/a
2016-08-12 2016-06-30 13F CENTURY ALUM COM Call 41,400 -43.98 262 -49.71 n/a n/a n/a
2016-05-12 2016-03-31 13F CENTURY ALUM COM Call 73,900 89.49 521 202.91 n/a n/a n/a
2016-02-11 2015-12-31 13F CENTURY ALUM COM Call 39,000 102.07 172 93.26 n/a n/a n/a
2015-11-20 2015-09-30 13F/A CENTURY ALUM COM Call 19,300 -7.66 89 -59.17 n/a n/a n/a
2015-11-06 2015-09-30 13F CENTURY ALUM COM Call 19,300 89 n/a n/a n/a
2015-08-11 2015-06-30 13F CENTURY ALUM COM Call 20,900 12.37 218 -15.18 n/a n/a n/a
2015-05-14 2015-03-31 13F CENTURY ALUM COM Call 18,600 -68.21 257 -81.99 n/a n/a n/a
2015-02-11 2014-12-31 13F CENTURY ALUM COM Call 58,500 16.30 1,427 9.26 n/a n/a n/a
2014-10-31 2014-09-30 13F CENTURY ALUM COM Call 50,300 1,306 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-11 2025-12-31 13F CENTURY ALUM COM Put 42,800 177.92 1,677 270.80 n/a n/a n/a
2025-11-12 2025-09-30 13F CENTURY ALUM COM Put 15,400 -72.40 452 -55.02 n/a n/a n/a
2025-08-14 2025-06-30 13F CENTURY ALUM COM Put 55,800 708.70 1,006 685.16 n/a n/a n/a
2025-05-14 2025-03-31 13F CENTURY ALUM COM Put 6,900 -17.86 128 -16.34 n/a n/a n/a
2025-05-14 2024-12-31 13F/A CENTURY ALUM COM Put 8,400 154.55 153 188.68 n/a n/a n/a
2025-02-14 2024-12-31 13F CENTURY ALUM COM Put 8,400 153 n/a n/a n/a
2024-11-14 2024-09-30 13F CENTURY ALUM COM Put 3,300 135.71 54 130.43 n/a n/a n/a
2024-08-14 2024-06-30 13F CENTURY ALUM COM Put 1,400 -89.06 23 -88.27 n/a n/a n/a
2024-05-10 2024-03-31 13F CENTURY ALUM COM Put 12,800 -60.98 197 -50.75 n/a n/a n/a
2024-02-14 2023-12-31 13F CENTURY ALUM COM Put 32,800 -28.54 398 20.61 n/a n/a n/a
2023-11-09 2023-09-30 13F CENTURY ALUM COM Put 45,900 427.59 330 340.00 n/a n/a n/a
2023-08-09 2023-06-30 13F CENTURY ALUM COM Put 8,700 -87.73 76 -89.42 n/a n/a n/a
2023-05-12 2023-03-31 13F CENTURY ALUM COM Put 70,900 -53.17 709 -42.73 n/a n/a n/a
2023-02-09 2022-12-31 13F CENTURY ALUM COM Put 151,400 33.04 1,238 105.99 n/a n/a n/a
2022-11-09 2022-09-30 13F CENTURY ALUM COM Put 113,800 315.33 601 197.52 n/a n/a n/a
2022-08-11 2022-06-30 13F CENTURY ALUM COM Put 27,400 -66.09 202 -90.50 n/a n/a n/a
2022-05-12 2022-03-31 13F CENTURY ALUM COM Put 80,800 648.15 2,126 1,087.71 n/a n/a n/a
2022-02-11 2021-12-31 13F CENTURY ALUM COM Put 10,800 -55.74 179 -45.43 n/a n/a n/a
2021-11-12 2021-09-30 13F CENTURY ALUM COM Put 24,400 190.48 328 203.70 n/a n/a n/a
2021-08-10 2021-06-30 13F CENTURY ALUM COM Put 8,400 27.27 108 -7.69 n/a n/a n/a
2021-05-12 2021-03-31 13F CENTURY ALUM COM Put 6,600 1,000.00 117 1,571.43 n/a n/a n/a
2021-02-10 2020-12-31 13F CENTURY ALUM COM Put 600 200.00 7 600.00 n/a n/a n/a
2020-11-12 2020-09-30 13F CENTURY ALUM COM Put 200 -60.00 1 -75.00 n/a n/a n/a
2020-08-13 2020-06-30 13F CENTURY ALUM COM Put 500 -61.54 4 -55.56 n/a n/a n/a
2019-08-09 2019-06-30 13F CENTURY ALUM COM Put 1,300 62.50 9 28.57 n/a n/a n/a
2019-05-14 2019-03-31 13F/A CENTURY ALUM COM Put 800 -97.83 7 -97.40 n/a n/a n/a
2019-05-13 2019-03-31 13F CENTURY ALUM COM Put 800 7 n/a n/a n/a
2019-02-05 2018-12-31 13F CENTURY ALUM COM Put 36,800 3.37 269 -36.85 n/a n/a n/a
2018-11-08 2018-09-30 13F CENTURY ALUM COM Put 35,600 673.91 426 491.67 n/a n/a n/a
2018-08-13 2018-06-30 13F CENTURY ALUM COM Put 4,600 -70.70 72 -72.31 n/a n/a n/a
2018-05-16 2018-03-31 13F/A CENTURY ALUM COM Put 15,700 423.33 260 340.68 n/a n/a n/a
2018-05-10 2018-03-31 13F CENTURY ALUM COM Put 15,700 260 n/a n/a n/a
2018-02-09 2017-12-31 13F CENTURY ALUM COM Put 3,000 -70.00 59 -64.46 n/a n/a n/a
2017-11-15 2017-09-30 13F CENTURY ALUM COM Put 10,000 -55.16 166 -52.16 n/a n/a n/a
2017-08-14 2017-06-30 13F CENTURY ALUM COM Put 22,300 347 n/a n/a n/a
2017-05-10 2017-03-31 13F CENTURY ALUM COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-02-15 2016-12-31 13F CENTURY ALUM COM Put 2,200 -73.81 19 -67.24 n/a n/a n/a
2016-11-14 2016-09-30 13F CENTURY ALUM COM Put 8,400 300.00 58 346.15 n/a n/a n/a
2016-08-12 2016-06-30 13F CENTURY ALUM COM Put 2,100 40.00 13 18.18 n/a n/a n/a
2016-05-12 2016-03-31 13F CENTURY ALUM COM Put 1,500 -83.87 11 -73.17 n/a n/a n/a
2016-02-11 2015-12-31 13F CENTURY ALUM COM Put 9,300 -68.47 41 -69.85 n/a n/a n/a
2015-11-20 2015-09-30 13F/A CENTURY ALUM COM Put 29,500 3.51 136 -54.21 n/a n/a n/a
2015-11-06 2015-09-30 13F CENTURY ALUM COM Put 29,500 136 n/a n/a n/a
2015-08-11 2015-06-30 13F CENTURY ALUM COM Put 28,500 25.00 297 -5.71 n/a n/a n/a
2015-05-14 2015-03-31 13F CENTURY ALUM COM Put 22,800 293.10 315 121.83 n/a n/a n/a
2015-02-11 2014-12-31 13F CENTURY ALUM COM Put 5,800 142 n/a n/a n/a
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.