The Stockholm Stock Exchange traded lower on Monday, tracking leading European bourses. Fresh threats of US tariffs against European automakers pressured Volvo Cars, while a takeover bid for Nilörn sent the stock soaring.

According to Iran, a US warship was struck by missiles in the Strait of Hormuz after ignoring Iranian warnings. The news caused the Stockholm Stock Exchange to retreat, before recovering slightly following a US denial.

At the close, the OMXS30 index was down 0.82 percent at 3,035.49. Shares worth approximately SEK 26.6 billion changed hands on the Stockholm Stock Exchange.

The best performer among the exchange's major industrial sectors was technology, with a 1.5 percent gain. At the other end of the spectrum, basic materials lagged with a 1.4 percent decline.

Among the blue-chip stocks included in the OMXS30 index, Nibe B rose 11.4 percent while EQT gained 4.0 percent. The weakest performers were Industrivärden C, down 2.7 percent, and Sandvik, which fell 2.6 percent.

Defense firm Saab may be heading toward one of its largest deals ever, involving up to 150 Gripen fighter jets for Ukraine. CEO Micael Johansson disclosed this on the SVT program 'Alex möter' with Alexander Norén. A deal is reportedly expected to be finalized within a few months. The stock rose 2.2 percent.

Volvo Cars was pressured by reports that the US may impose new 25 percent tariffs on European automakers. The stock fell 1.1 percent.

Construction group Skanska has signed an agreement with atNorth to expand a data center in Espoo, Finland, with a contract value of SEK 1.1 billion. Skanska has also secured an order for the Hudson Tunnel Project in New York, worth SEK 3.4 billion to the company. The stock increased 0.4 percent.

Trimco Group has launched a takeover bid for all shares in label manufacturer Nilörn at SEK 77 per share. This represents a bid premium of 53 percent against the last closing price. The board recommends that shareholders accept the offer. The stock surged 49.2 percent.

Polymer company Hexpol saw its first-quarter operating profit decrease more than expected to SEK 701 million. Revenue was in line with expectations. The stock rose 0.1 percent.

The board of gambling supplier Hacksaw has decided to dismiss President and CEO Christoffer Källberg from his position. Board member Ana Vrabic Verdir takes over as acting CEO. Hacksaw has initiated a comprehensive recruitment process to appoint a permanent CEO. The announcement came after Thursday's close. The stock fell 5 percent.

Cybersecurity firm Yubico and AI company OpenAI are entering into a long-term partnership regarding hardware-based authentication. OpenAI users can now purchase specially designed security keys to protect their accounts against phishing attacks. The stock rose 14.3 percent.

Poultry company Scandi Standard has acquired Danbroiler, which has a turnover of SEK 86 million and a capacity of 3.5 million chickens per year. The stock fell 0.4 percent.

Investment company Ratos' adjusted EBITA for the first quarter of 2026 came in higher than analyst expectations. Revenue was in line with consensus. The stock fell 2.3 percent.

Real estate company Stendörren reported a solid increase in rental income and profit from property management in the first quarter compared to the same quarter last year. The stock retreated 4.1 percent.

Sivers Semiconductors surged 47.2 percent on Monday, crossing the SEK 50 mark.

On the analyst front, Handelsbanken has upgraded Camurus to buy from hold, raising the target price to SEK 700 from SEK 600. The stock rose 3.1 percent.

Pareto has raised its recommendation for Paradox to buy from hold. The stock rose 1.9 percent.

Dagens industri recommends a buy for lock manufacturer Assa Abloy under its 'Share of the Week' column. The stock fell 0.3 percent.