Wall Street Boosted By Trump Tariffs

US stocks finished a volatile session higher on Thursday after President Donald Trump enacted controversial tariffs on imported steel and aluminum amid worries the move could ignite a global trade war.

The Dow Jones advanced 0.4 percent to 24,895.

The S&P 500 gained 0.5 percent to 2,738, while the Nasdaq increased 0.4 percent to 7,427.

US stocks have been pressured since Trump first announced plans to enact the tariffs a week ago.

Analysts pointed to softening rhetoric from Trump and his aides over the last day, including a temporary exemption for Mexico and Canada while the countries renegotiate the North American Free Trade Agreement.

"I have a feeling we're going to make a deal on Nafta," Trump said during a tariff signing event on Thursday afternoon.

"I said it for a long time: Make a deal or we terminate, and if we do (make a deal), there's no tariffs on Canada, there's no tariffs on Mexico."

Karl Haeling, vice president of LBBW, said the exemptions and other possible carve outs mean, "there would be hardly any import tariffs put on."

But FTN Financial chief economist Chris Low said investors remained unnerved by Trump's actions, which have sparked threats of retaliation from other trading partners.

"Let's see what the next shoe is to drop," Low said. "Maybe (Trump is) dialling back the concern, but there's no question investors are nervous about the possibility of a trade war."

Shares of steel companies fell, with some commentators suggesting that the tariffs might not be strong enough to help the industry. United States Steel and Nucor both dropped almost three percent.

There was little pattern among companies that rely on aluminum and steel imports with Ford ending modestly lower and General Motors and Boeing both up less than one percent.

Express Scripts surged 8.6 percent following its agreement to be acquired by Cigna for about US$67 billion in the latest big deal in the health care sector. Cigna fell 11.4 percent.

Supermarket chain Kroger slumped 12.4 percent after projecting 2018 earnings between US$1.95 and US$2.15 a share, below some analyst expectations. (AFP)