Drilling company Transocean jumped 3.9 percent and oil producers Apache and ConocoPhillips rose more than 2 percent as oil prices continued to climb after last week's OPEC agreement to cut output.
Banking shares also continued an upward push as expectations firm that the US Federal Reserve will raise interest rates later this month. Goldman Sachs gained 2.3 percent, Bank of America 2.7 percent and JPMorgan Chase 1.8 percent.
About 25 minutes into trading, the Dow Jones Industrial Average was up 0.5 percent to 19,261.29, above Thursday's record close.
The broad-based S&P 500 gained 0.7 percent to 2,206.60, while the tech-rich Nasdaq Composite Index advanced 0.9 percent to 5,304.03.
Briefing.com analyst Patrick O'Hare said markets were taking a wait-and-see approach to the Italian vote -- which rejected the proposed reforms and led to the resignation of Prime Minister Matteo Renzi -- due to the market's resiliency in the face of earlier surprise votes in Britain and the United States.
"Participants recognize that it has paid handsomely to trade against the grain of conventional wisdom highlighting the market risks associated with presumably adverse political outcomes," O'Hare said.
Copyright AFP (Agence France-Presse), 2016