Russian stocks drop on S&P junk rating

Russian stocks tumbled the most in six weeks in US trading, led by OAO Sberbank, after Standard & Poor's lowered the country's credit rating to junk.

The Bloomberg Russia-US Equity Index fell 5.5 percent on Monday, the most since Dec 16. Sberbank's American depositary receipts retreated 13 percent on volumes 1.7 times the average of the past three months. Rouble forwards declined 2.4 percent as of 12:14 pm in Hong Kong.

Stocks sank and the rouble closed at a record low on Monday after S&P cut Russia one step to BB+ with a negative outlook. The ratings company said in a statement that the cut reflects its view that the country's "monetary policy flexibility has become more limited and its economic growth prospects have weakened". Gross domestic product is projected to shrink this year as declining oil prices exacerbate the impact of sanctions linked to the conflict in Ukraine.