On August 18, Alcoa declined 5.4% in regular trading, trading at $49.04/share, with turnover of approximately $39.96 million. The stock had opened at $50.20 and reached an intraday high of $51.84 before reversing sharply lower.

The decline was triggered by reports that the US Commerce Department imposed tariffs on 407 categories of steel and aluminum products, with Alcoa facing an estimated $115 million increase in costs. The tariff action also raised concerns about potential disruption in global aluminum trade flows, including approximately 3 million tons of Chinese re-export trade volumes.

The broader aluminum sector experienced widespread selling pressure in response to the policy announcement. Century Aluminum fell 5.68%, Kaiser Aluminum plunged 14.9%, and Constellium NV dropped 6.62%. The sector-wide weakness underscores market concern that increased tariff costs may compress margins across the domestic aluminum industry despite the protectionist intent of the measures.

(The above content is based on publicly available market information, generated by a program or algorithm, and is intended solely as a stock movement alert. It does not constitute investment advice or a basis for trading decisions.)