Forex Market Update

The dollar rose to new record highs against the ruble Monday, as unraveling oil prices were compounded by fears that some of Russia’s largest companies could default on their dollar-denominated debts.

In recent trade, the dollar rose to 65.5870 rubles RUBUSD, +6.41%   — its highest level ever — as the price of West Texas Intermediate crude oil for January delivery sunk below $56 a barrel. The dollar was worth 58 rubles Friday.

Worries about the falling price of oil pushed the dollar lower against the yen Monday. The buck USDJPY, -0.52%  was worth 117.64 yen Monday, compared to ¥118.80 Friday.

The ICE U.S. Dollar Index DXY, -0.17%  , a measure of the greenback’s strength against a basket of six currencies, was flat for the day at 88.4360.