NEW YORK — U.S. stocks are opening moderately lower as the price of oil continues to drop.

The ruble kept plunging against the dollar Tuesday even after Russia's central bank sharply raised a key interest rate in an effort to shore up the currency.

The Dow Jones industrial average fell 74 points, or 0.4 percent, to 17,108 as of 9:35 a.m. Eastern time.

The Standard & Poor's 500 index fell nine points, or 0.5 percent, to 1,980. The Nasdaq composite lost 22 points, or 0.5 percent, to 4,582.

The price of crude oil sank $1.87, or 3.3 percent, to $54.05 a barrel in New York. Oil has fallen by nearly half since June.

Bond prices rose. The yield on the 10-year Treasury note fell to 2.06 percent.