Summary

The S&P 500 and the Dow Jones Industrial Average were lower at the end of the trading day on Monday as the tariffs signed into law last week weighed on industrials, though gains in tech stocks helped to push the Nasdaq higher.

Shares of Boeing, down 2.9 percent, and Caterpillar, down 2.4 percent, have been under pressure as Trump’s protectionist stance on steel and aluminum imports could increase costs and hamper sales abroad. Boeing and Caterpillar were worst performers on the Dow.

Trump last week softened his stance on tariffs by exempting Canada and Mexico, and negotiations were ongoing as the European Union and Japan also seek exemptions.

Concerns over possible fallout from the tariffs largely supplanted optimism, based upon the modest wage growth numbers from Friday’s employment report, that the Federal Reserve would stick to its projected three interest-rate increases in 2018.

Even with the session’s losses, the S&P 500 is just 3.1 percent below record highs hit on Jan. 26, while the Nasdaq has recovered its losses from last month’s sell-off. The tech-heavy Nasdaq was lifted in part by further signs of official disapproval of Broadcom’s $117 billion bid for Qualcomm.

The Treasury Department said in a letter to Singapore-based Broadcom that it had confirmed national security concerns about the bid and that the company had not given sufficient notice of its plans to redomicile in the United States. Broadcom gained 3.6 percent while shares in Qualcomm were flat.

Shares of Micron Technology rose 8.8 percent to $59.37 after analysts at Nomura raised their target for the stock to $100.

Oclaro closed up 27.5 percent after laser and optical fiber specialist Lumentum Holdings said it planned to acquire the optical components producer for $1.7 billion. Lumentum’s shares rose 4.4 percent.

Approximately 6.52 billion shares changed hands on the major domestic equity exchanges, as compared a 7.2 billion share average over the last 20 trading days.