S&P 500 opens with small gains near 3,700

• Wall Street's main indexes trade mixed on Tuesday.
• Energy shares post strong gains on surging crude oil prices.

Major equity indexes in the US opened on a mixed note on Tuesday as investors remain cautious while waiting for the results of the runoff election in Georgia, which will determine if Democrats will retain the majority in Senate.

As of writing, the Dow Jones Industrial Average was up 0.18% at 30,281, the S&P 500 Index was gaining 0.15% at 3,706 and the Nasdaq Composite was posting small losses at 12,700.

Among the 11 major sectors, the Energy Index is up 1.8% after the opening bell on surging crude oil prices. On the back of reports suggesting that Russia and Saudi Arabia reached an agreement to keep the oil output steady in February, the barrel of West Texas Intermediate is up more than 4% at $49.25.

Later in the session, the ISM's December Manufacturing PMI report will be looked upon for fresh impetus.

S&P 500 chart (daily)