US stocks bounced up and down and finished mostly lower on Wednesday as technology companies slumped.
Commerce Secretary Wilbur Ross discussed a more nationalist trade stance, with uncertain effects for the market.
The dollar, already at three-year lows, got even weaker.
Stocks got off to a strong start, but technology companies took heavier losses as the day wore on, led by chipmakers after Texas Instruments gave a disappointing forecast for the current quarter. Apple also fell.
The dollar sagged against other currencies after Treasury Secretary Steven Mnuchin said the currency’s decline is good for US exporters, suggesting he is not likely to try to stop its slide.
Airlines plunged after United Continental said it plans to ramp up passenger capacity.
Mr Mnuchin and Mr Ross are at the World Economic Forum in Davos, Switzerland.
Mr Mnuchin’s comments sent the price of gold and silver higher, as investors often buy precious metals when they are concerned about inflation or softness in the dollar.
Weakness in the dollar usually helps companies that export a lot of goods from the US but it can hurt smaller, more domestic companies by driving up the costs of imported components.
“Small caps are much more domestically focused than large caps are, but (they are) still buying from foreign companies,” said Mark Hackett, chief of investment research at Nationwide Investment Management.
Mr Hackett said smaller US companies will report faster profit growth this year than larger ones.
That is because the benefit those companies will get from the recent corporate tax cut will outweigh the pain from the weaker dollar.
The Standard & Poor’s 500 index lost 1.59 points, or 0.1%, to 2,837.54.
The Dow Jones industrial average rose 41.31 points, or 0.2%, to 26,252.12.
In the morning the Dow rose as much as 181 points and later fell as much as 103 points before turning higher again. That’s an unusually large swing for the Dow given the market’s recent lack of volatility.
The Nasdaq composite fell 45.23 points, or 0.6%, to 7,415.06. The Russell 2000 index of smaller-company stocks skidded 11.10 points, or 0.7%, to 1,599.61.
