US stocks bounced up and down and finished mostly lower 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 chip makers after Texas Instruments gave a disappointing forecast for the current quarter and fell 8.5 percent. Competitor Applied Materials lost 1.5 percent, and Nvidia fell 1.3 percent. Apple declined 1.6 percent.
Chip makers have made huge gains in recent months, however, and Nvidia has more than doubled over the past year.
The dollar sagged against other currencies after Treasury Secretary Steven Mnuchin said the currency’s decline is good for US exporters, suggesting he isn’t likely to try to stop the slide.
Airlines fell after United Continental said it’s planning to increase its passenger capacity 4 to 6 percent a year through 2020. United has done better recently at handling competition with lower-cost carriers, but investors worried that more flights will mean reduced prices and hurt profits. United Continental plunged 11.4 percent.
Mnuchin and Ross are at the World Economic Forum in Davos, Switzerland. Mnuchin’s comments sent the price of gold and silver higher; investors often buy precious metals when they’re concerned about inflation or softness in the dollar. Weakness in the dollar usually helps US exporters but it can hurt smaller, more domestic companies by driving up the costs of imported components.
The Standard & Poor’s 500 index lost 0.1 percent, to 2,837.54. The Dow Jones industrial average rose 0.2 percent, 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 — an unusually large swing, given the market’s recent lack of volatility.
The Nasdaq Composite fell 0.6 percent, to 7,415.06. The Russell 2000 index of smaller-company stocks slipped 0.7 percent, to 1,599.61.
Investors have focused on global trade issues the last few days. On Tuesday, the administration placed tariffs on imported solar power components and washing machines.
On Wednesday, Ross said the United States is fighting back against countries that have taken advantage of trade deals.
‘‘Trade wars are fought every single day,’’ Ross said. ‘‘Unfortunately, every single day there are various parties trying to violate the rules, and trying to take unfair advantage of things . . . the difference is that US troops are now coming to the ramparts.’’
European stocks dropped. Germany’s DAX slumped 1.1 percent, and the French CAC 40 fell 0.7 percent. The British FTSE 100 fell 1.1 percent.
The dollar dropped to 109.05 yen from 110.30 yen. The euro advanced to $1.2405 from $1.2294. The ICE US dollar index fell almost 10 percent in 2017 and is down 3 percent so far this year.
Gold climbed $19.60, or 1.5 percent, to $1,356.30 an ounce, and silver rose 58 cents, or 3.4 percent, to $17.49 an ounce.
Bond prices fell. The yield on the 10-year Treasury note rose to 2.64 percent from 2.62 percent. That helped banks because higher yields let them charge higher interest rates on loans. JPMorgan Chase rose $1.46, or 1.3 percent, to $115.67.