U.S. stock indices rose in a volatile session on Wednesday. Some analysts say that stocks have been following energy prices over the past few days.

The Dow Jones Industrial Average rose 122.10 points, or 0.7%, to 16,912.29. The S&P 500 advanced by 15.91, or 0.8%, to 1,995.83. The Nasdaq Composite Index rose 42.79, or 0.9%, to 4,791.15.

Moody's Investor Service affirmed credit rating of the U.S. at "AAA", outlook stable. Moody's explained that the high rating is supported by strong GDP growth, strong dollar and reliable bonds. Nevertheless the agency noted potential threats to the rating in the long-term period.

Meanwhile investors are preparing for third quarter earnings reports. Aluminum producer Alcoa will traditionally report first. Its data will be published on Thursday after trading stops.

This morning in Asia Hong Kong Hang Seng fell 0.69%, or 155.13, to 22,360.63. China Shanghai Composite Index added 3.80%, or 116.11, to 3.168.89. The Nikkei lost 0.78%, or 142.56, to 18,180.42.

Asian indices posted mixed results. Chinese stocks rose after markets reopened after National Day holidays.

Japanese stocks declined amid weak machinery orders data. The corresponding index fell by 5.7% in August, while economists had expected it to grow by 3.2%. On an annualized basis orders fell by 3.5% vs expectations for a 4.2% rise.

Yesterday the Bank of Japan lowered its assessment of business confidence noting some cautiousness. However on the whole assessment remained positive.