S&P 500 opens modestly higher above 3,100

• Wall Street's main indexes look to extend rally into fourth straight day.
• CBOE Volatility Index continues to edge lower on Wednesday.
• S&P 500 Energy Index drops more than 1% as crude oil's recovery loses steam.

Major equity indexes in the United States started the day modestly higher on Wednesday as investors seem to be looking to book their profits following the impressive rally witnessed earlier this week. As of writing, the S&P 500 was up 0.1% on the day at 3,127 points, the Dow Jones Industrial Average was flat and the Nasdaq Composite was gaining 0.45% at 9,945 points.

Energy shares remain on the back foot

The CBOE Volatility Index, Wall Street's fear gauge, is modestly lower on the day to reflect the lack of risk-appetite.

Among the 11-major S&P 500 sectors, the Energy Index is down 1.6% on the day as the top-decliner. The poor performance of crude oil prices seems to be weighing on energy shares. On the other hand, the Technology and the Consumer Discretionary indexes are both around 0.5%.

Later in the day, Jerome Powell, Chairman of the Federal Reserve System, will be testifying before the Senate as part of the FOMC's semiannual monetary policy report.