Derivatives

3 Months Ended

Mar. 31, 2026

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives

11.    Derivatives

As of March 31, 2026, we had an open position of 59,500 tonnes related to LME forward financial sales contracts to fix the forward LME aluminum price. These contracts are expected to settle monthly through December 2027. We also had an open position of 99,400 tonnes related to MWP forward financial sales contracts to fix the forward MWP price. These contracts are expected to settle monthly through December 2027. We also enter into financial contracts with various counterparties to offset fixed price sales arrangements with certain of our customers ("fixed for floating swaps") to remain exposed to the LME and MWP aluminum prices. As of March 31, 2026, we had 100 tonnes open fixed for floating swaps. These contracts are expected to settle monthly through August 2026.

We have entered into financial contracts to hedge a portion of our Jamalco fuel cost exposure ("HFO price swaps"). The volume of heavy fuel oil ("HFO") consumed at Jamalco is measured per barrel and as of March 31, 2026, we had an open position of 150,000 barrels. The HFO price swaps are expected to settle monthly through October 2026.

We have entered into financial contracts to fix a portion of our exposure to the Indiana Hub power market at our Sebree plant ("Indiana Hub power price swaps"). As of March 31, 2026, we had an open position of 957,552 MWh. The Indiana Hub power price swaps are expected to settle monthly through December 2027.

Our agreements with derivative counterparties contain certain provisions requiring collateral to be posted in the event the market value of our position exceeds the margin threshold limit of our master agreement with the counterparty. As of March 31, 2026 and December 31, 2025, the Company had no recorded restricted cash as collateral related to open derivative contracts under the master arrangements with our counterparties.

The following tables set forth the Company's derivative assets and liabilities that were accounted for at fair value and not designated as cash flow hedges as of March 31, 2026 and December 31, 2025, respectively:

	Asset Fair Value
	March 31, 2026		December 31, 2025
Commodity contracts(1)	$	8.2	$	1.9

	Liability Fair Value
	March 31, 2026		December 31, 2025
Commodity contracts(1)	$	120.6	$	66.0

(1)Commodity contracts reflect our outstanding LME and MWP forward financial sales contracts, Indiana Hub power price swaps, fixed for floating swaps, and HFO price swaps.

The following table summarizes the net loss on forward and derivative contracts:

	Three months ended March 31,
	2026		2025
Commodity contracts	$	(65.3)	$	(5.5)