Kaiser Aluminum Corporation
US ˙ NasdaqGS ˙ US4830077040

SecurityKALU / Kaiser Aluminum Corporation
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership7,768 shares
Latest Disclosed Value $ 936,121
Simplex Trading, Llc ownership in KALU / Kaiser Aluminum Corporation

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 7,768 shares of Kaiser Aluminum Corporation (US:KALU) valued at $936,122 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 7,520 shares of Kaiser Aluminum Corporation. This represents a change in shares of 3.30% during the quarter. The current value of the position is $1,451,451 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (KALU) in the form of stock options. The firm currently holds call options representing 100 of underlying shares valued at $12,051 USD and put options representing 100 of underlying shares valued at $12,051 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.

KALU / Kaiser Aluminum Corporation 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)
2026-05-14 2026-03-31 13F KAISER ALUMINIUM COM 483007704 7,768 248 3.30 936 8.46 0.0003
2026-02-11 2025-12-31 13F KAISER ALUMINUM COM 483007704 7,520 7,005 1,360.19 864 0.0005
2025-11-12 2025-09-30 13F KAISER ALUMINUM COM 483007704 515 344 201.17 0 0.0000
2025-08-05 2025-06-30 13F KAISER ALUMINUM COM 483007704 171 -42 -19.72 0 0.0000
2025-05-12 2025-03-31 13F KAISER ALUMINUM COM 483007704 213 103 93.64 0 0.0000
2025-02-11 2024-12-31 13F KAISER ALUMINUM COM 483007704 110 22 25.00 0 0.0000
2024-11-08 2024-09-30 13F KAISER ALUMINUM COM 483007704 88 54 158.82 0 0.0000
2024-07-25 2024-06-30 13F KAISER ALUMINUM COM 483007704 34 34 0 0.0000
2024-02-02 2023-12-31 13F KAISER ALUMINUM COM 483007704 0 -127 -100.00 0 0.0000
2023-11-01 2023-09-30 13F KAISER ALUMINUM COM 483007704 127 127 0 0.0000
2023-02-02 2022-12-31 13F KAISER ALUMINUM COM 483007704 0 -234 -100.00 0 -100.00
2022-11-04 2022-09-30 13F KAISER ALUMINUM COM 483007704 234 -198 -45.83 14 -58.82 0.0000
2022-08-03 2022-06-30 13F KAISER ALUMINUM COM 483007704 432 -86 -16.60 34 -29.17 0.0000
2022-05-02 2022-03-31 13F KAISER ALUMINUM COM 483007704 518 -300 -36.67 48 -36.84 0.0000
2022-02-23 2021-12-31 13F/A-1 KAISER ALUMINUM COM 483007704 818 387 89.79 76 43.40 0.0001
2022-02-04 2021-12-31 13F KAISER ALUMINUM COM 483007704 431 0 53 0.0000
2021-10-28 2021-09-30 13F KAISER ALUMINUM COM 483007704 431 0 0.00 53 0.00 0.0000
2021-08-12 2021-06-30 13F KAISER ALUMINUM COM 483007704 431 401 1,336.67 53 1,666.67 0.0001
2021-04-26 2021-03-31 13F KAISER ALUMINUM COM 483007704 30 -1,148 -97.45 3 -97.41 0.0000
2021-02-02 2020-12-31 13F KAISER ALUMINUM COM 483007704 1,178 1,178 116 0.0002
2019-04-18 2019-03-31 13F KAISER ALUMINUM COM 483007704 0 -313 -100.00 0 -100.00
2019-01-16 2018-12-31 13F KAISER ALUMINUM COM 483007704 313 313 27 0.0001
2018-04-26 2018-03-31 13F KAISER ALUMINUM COM 483007704 0 -1,090 -100.00 0 -100.00
2018-01-10 2017-12-31 13F KAISER ALUMINUM COM 483007704 1,090 354 48.10 116 54.67 0.0050
2017-10-25 2017-09-30 13F KAISER ALUMINUM COM 483007704 736 736 -32.48 75 -35.34 0.0031
2017-01-11 2016-12-31 13F KAISER ALUMINUM COM 483007704 0 -197 -100.00 0 -100.00
2016-10-07 2016-09-30 13F KAISER ALUMINUM COM 483007704 197 197 0.00 17 0.0012
2015-07-08 2015-06-30 13F KAISER ALUMINUM COM 483007704 0 -85 -100.00 0 -100.00
2015-04-21 2015-03-31 13F KAISER ALUMINUM COM 483007704 85 27 46.55 6 50.00 0.0007
2015-03-04 2014-12-31 13F KAISER ALUMINUM COM 483007704 58 58 4 0.0005
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
(%)
2026-05-14 2026-03-31 13F KAISER ALUMINIUM CALL Call 100 12 n/a n/a n/a
2026-02-11 2025-12-31 13F KAISER ALUMINUM CALL Call 0 -100.00 0 n/a n/a n/a
2025-11-12 2025-09-30 13F KAISER ALUMINUM CALL Call 600 0 n/a n/a n/a
2024-11-08 2024-09-30 13F KAISER ALUMINUM CALL Call 0 -100.00 0 n/a n/a n/a
2024-07-25 2024-06-30 13F KAISER ALUMINUM CALL Call 100 0 n/a n/a n/a
2024-04-25 2024-03-31 13F KAISER ALUMINUM CALL Call 0 -100.00 0 n/a n/a n/a
2024-02-02 2023-12-31 13F KAISER ALUMINUM CALL Call 13,700 1 n/a n/a n/a
2023-04-27 2023-03-31 13F KAISER ALUMINUM CALL Call 0 -100.00 0 n/a n/a n/a
2023-02-02 2022-12-31 13F KAISER ALUMINUM CALL Call 600 200.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F KAISER ALUMINUM CALL Call 200 -33.33 12 -47.83 n/a n/a n/a
2022-08-03 2022-06-30 13F KAISER ALUMINUM CALL Call 300 200.00 23 155.56 n/a n/a n/a
2022-05-02 2022-03-31 13F KAISER ALUMINUM CALL Call 100 -75.00 9 -81.63 n/a n/a n/a
2022-02-04 2021-12-31 13F KAISER ALUMINUM CALL Call 400 0.00 49 0.00 n/a n/a n/a
2021-10-28 2021-09-30 13F KAISER ALUMINUM CALL Call 400 0.00 49 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F KAISER ALUMINUM CALL Call 400 49 n/a n/a n/a
2021-02-02 2020-12-31 13F KAISER ALUMINUM CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-10-14 2020-09-30 13F KAISER ALUMINUM CALL Call 1 5 n/a n/a n/a
2019-07-26 2019-06-30 13F KAISER ALUMINUM CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-04-18 2019-03-31 13F KAISER ALUMINUM CALL Call 5 52 n/a n/a n/a
2018-07-30 2018-06-30 13F KAISER ALUMINUM CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-04-26 2018-03-31 13F KAISER ALUMINUM CALL Call 9 800.00 0 n/a n/a n/a
2018-01-10 2017-12-31 13F KAISER ALUMINUM CALL Call 1 -90.00 0 -100.00 n/a n/a n/a
2017-10-25 2017-09-30 13F KAISER ALUMINUM CALL Call 10 900.00 4 n/a n/a n/a
2017-04-21 2017-03-31 13F KAISER ALUMINUM CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-01-11 2016-12-31 13F KAISER ALUMINUM CALL Call 2 0 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
(%)
2026-05-14 2026-03-31 13F KAISER ALUMINIUM PUT Put 100 -85.71 12 -85.00 n/a n/a n/a
2026-02-11 2025-12-31 13F KAISER ALUMINUM PUT Put 700 -56.25 80 n/a n/a n/a
2025-11-12 2025-09-30 13F KAISER ALUMINUM PUT Put 1,600 433.33 0 n/a n/a n/a
2025-08-05 2025-06-30 13F KAISER ALUMINUM PUT Put 300 0.00 0 n/a n/a n/a
2025-05-12 2025-03-31 13F KAISER ALUMINUM PUT Put 300 -82.35 0 n/a n/a n/a
2025-02-11 2024-12-31 13F KAISER ALUMINUM PUT Put 1,700 0.00 0 n/a n/a n/a
2024-11-08 2024-09-30 13F KAISER ALUMINUM PUT Put 1,700 466.67 0 n/a n/a n/a
2024-07-25 2024-06-30 13F KAISER ALUMINUM PUT Put 300 0 n/a n/a n/a
2024-04-25 2024-03-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 n/a n/a n/a
2024-02-02 2023-12-31 13F KAISER ALUMINUM PUT Put 100 -66.67 0 n/a n/a n/a
2023-11-01 2023-09-30 13F KAISER ALUMINUM PUT Put 300 200.00 0 n/a n/a n/a
2023-08-04 2023-06-30 13F KAISER ALUMINUM PUT Put 100 -50.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F KAISER ALUMINUM PUT Put 200 0 n/a n/a n/a
2023-02-02 2022-12-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F KAISER ALUMINUM PUT Put 600 0.00 36 -23.40 n/a n/a n/a
2022-08-03 2022-06-30 13F KAISER ALUMINUM PUT Put 600 -14.29 47 -27.69 n/a n/a n/a
2022-05-02 2022-03-31 13F KAISER ALUMINUM PUT Put 700 -12.50 65 -13.33 n/a n/a n/a
2022-02-23 2021-12-31 13F/A KAISER ALUMINUM PUT Put 800 75 n/a n/a n/a
2021-02-02 2020-12-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-10-14 2020-09-30 13F KAISER ALUMINUM PUT Put 5 -94.62 26 -96.20 n/a n/a n/a
2020-07-13 2020-06-30 13F KAISER ALUMINUM PUT Put 93 1,760.00 684 2,530.77 n/a n/a n/a
2020-04-28 2020-03-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-05 2019-12-31 13F KAISER ALUMINUM PUT Put 1 -90.00 11 n/a n/a n/a
2019-10-15 2019-09-30 13F KAISER ALUMINUM PUT Put 10 0 n/a n/a n/a
2019-07-26 2019-06-30 13F KAISER ALUMINUM PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-04-18 2019-03-31 13F KAISER ALUMINUM PUT Put 40 566.67 418 688.68 n/a n/a n/a
2019-01-16 2018-12-31 13F KAISER ALUMINUM PUT Put 6 500.00 53 430.00 n/a n/a n/a
2018-10-23 2018-09-30 13F KAISER ALUMINUM PUT Put 1 -75.00 10 -75.61 n/a n/a n/a
2018-07-30 2018-06-30 13F KAISER ALUMINUM PUT Put 4 300.00 41 310.00 n/a n/a n/a
2018-04-26 2018-03-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F KAISER ALUMINUM PUT Put 51 0.00 0 n/a n/a n/a
2017-07-12 2017-06-30 13F KAISER ALUMINUM PUT Put 0 -100.00 0 n/a n/a n/a
2017-04-21 2017-03-31 13F KAISER ALUMINUM PUT Put 53 0 n/a n/a n/a
2016-07-18 2016-06-30 13F KAISER ALUMINUM PUT Put 0 -100.00 0 n/a n/a n/a
2016-04-14 2016-03-31 13F KAISER ALUMINUM PUT Put 6 0.00 0 n/a n/a n/a
2016-01-20 2015-12-31 13F KAISER ALUMINUM PUT Put 0 -100.00 0 n/a n/a n/a
2015-10-08 2015-09-30 13F KAISER ALUMINUM PUT Put 3 0 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.