Why is BAE Systems stock sliding today?

BAE Systems stock fell 4.0% to trade at 1,992p after Democrats secured majorities in both the U.S. Senate and the House of Representatives in Tuesday’s midterm elections, dealing a significant blow to President Trump’s defence spending agenda and triggering a sharp sector-wide retreat among European defence companies.

Investors fear that Democratic control of Congress could bring heightened scrutiny to the large military spending commitments that have been a key growth driver for BAE and its peers.

The sell-off was not isolated to BAE Systems — the entire European aerospace and defence sector came under pressure, with rivals including Thales, Babcock, Saab, Rheinmetall, Chemring, and Avon Technologies all declining meaningfully.

Adding to the headwinds, renewed US strikes on Iran raised concerns about a potential return to broader Middle Eastern conflict, contributing to a cautious risk environment that weighed on defence valuations across the board.

The FTSE 100 itself managed to edge slightly higher on the day, rising to approximately 10,647, as gains in precious metal miners and banking stocks — which benefited from a weaker dollar and expectations of a steeper yield curve — partially offset the drag from defence names.

The Bank of England’s upcoming rate decision later this week also kept broader market sentiment in check, with investors balancing geopolitical uncertainty against domestic monetary policy considerations.

Taken together, the combination of a politically altered US spending landscape, sector-wide contagion from peer declines, and a backdrop of elevated geopolitical risk created a challenging environment for BAE Systems today, pulling the stock to a session low of 1,953.5p — well below its 52-week high of 2,360p — even as the company’s own operational fundamentals, including a record £84bn order backlog and upgraded full-year earnings guidance, remain intact.