U.S. stocks are closing lower after a see-saw day, extending the market's losses to a fourth day.
European and Asian markets also fell Thursday after Saudi Arabia launched strikes on military installations in Yemen. The price of oil rose.
The Dow Jones industrial average gave up 40 points, or 0.2 percent, to 17,678.
The Standard & Poor's 500 lost four points, or 0.2 percent, to 2,056. The Nasdaq composite lost 13 points, or 0.3 percent, to 4,863.
The price of oil rose $2.22 to $51.43 a barrel in New York.
SanDisk plunged 18 percent, the most in the S&P 500, after the maker of flash memory chips cut its revenue forecast.
Bond prices fell. The yield on the 10-year Treasury note rose to an even 2 percent from 1.93 percent.