JPMorgan Chase is exiting physical commodities trading, the bank said, as Wall Street’s role in the trading of raw materials comes under intense political and regulatory pressure. The firm, Wall Street’s biggest bank, said an internal review had concluded it should pursue “strategic alternatives” for its physical commodities operations, which include assets like its Henry Bath metals warehousing subsidiary and a vast global team trading everything from African crude to Canadian natural gas. The firm will explore “a sale, spinoff or strategic partnership” for its physical arm, the statement said. The announcement, which surprised many, comes after a week of increased scrutiny of Wall Street’s commodity operations.