Dow closes down more than 400 points

Following US President Donald Trump's announcement of imposing a 25 percent tariff on imported steel and 10 percent on aluminium, major stock indexes plunged Thursday afternoon

Investor concern about the news rattled the Dow Jones industrial average, which closed the day's trading down 420.22 points lower at 24,608.98, after rising more than 150 points earlier in the day.

The 30-stock index fell as much as 586 points.

That is a three-day decline of 4.3 percent.

The S&P 500 dropped 3.67 percent over the three days. The tech-heavy Nasdaq Composite is down 3.25 percent.

"Traders are, again, focused on talk of tariffs while investors are focused on earnings growth, continuing low inflation and highly accommodative interest rates," said Daniel P. Wiener, chief executive officer of Adviser Investments, a Newton, Mass.-based firm that manages more than five billion dollars in assets, as quoted by Washington Post. "Volatility is back, but that shouldn't sway investors from their longer-range objectives."

The Dow was already reeling from a 380 point decline on Wednesday on fears of continued interest rate hikes by the Federal Reserve.

New Fed chairman Jerome Powell spoke this week before Congress, where he left open the possibility of four rate hikes this year instead of three.