While you were sleeping: UPDATED Stocks, UK pound, oil soar on Brexit polls

Equities on both sides of the Atlantic advanced as the latest polls suggest British voters might now opt to keep the country in the European Union in a Thursday referendum.

Oil also rose, gold fell and the UK pound gained more than 2% on the US dollar.

After last Thursday's murder of Jo Cox, a pro-EU British member of Parliament, support for the Leave campaign, or Brexit, appears to have faded. A weekend poll showed 45% of voters support the UK's membership of the EU, while 42% backed withdrawal.

"The momentum for Brexit was so strong and it was suddenly broken, which caught everyone by surprise," Christian Gattiker, head of research at Julius Baer Group in Zurich, told Bloomberg.

"We were steering into a clear Brexit scenario and now we've seen a counter move that makes it more balanced, more in line with what investors thought in the first place."

Wall Street rises 130 points
On Wall Street, the Dow Jones Industrial Average climbed 129.71 points, or 1.1%, to 17,804.87 after earlier rising as much as 271points.

The Nasdaq Composite Index rallied 0.8% to 4837.21 and the Standard & Poor's 500 Index rose 0.6% to 2083.25.

Energy shares in the S&P 500 climbed 0.9% as the price of US crude oil rose 2.9% to $US49.37 a barrel. Marathon Oil gained 10% after the company said it would buy PayRock Energy Holdings for $US888 million.

Gold for June delivery retreated 0.2% to $US1290 an ounce. 

Gains in shares of Boeing and those of Goldman Sachs, up 2.7% and 2.1% respectively, led the Dow higher. As of midday trading in New York, shares of Verizon Communications were the only Dow stock to trade lower.

Boeing's two big deals
Iran has reached a deal to buy 100 planes from US aircraft manufacturer Boeing, and the two sides are awaiting approval by US Treasury authorities, according to state-owned news reports citing the head of Iran's Civil Aviation Organisation.

"The final obstacle in this area is only the permits from the US Treasury Department," Ali Abedzadeh told the state-owned newspaper Iran in remarks published on Sunday, according to Al Jazeera.

"We have been engaged in discussions with Iranian airlines approved by the USG about potential purchases of Boeing commercial passenger airplanes and services," Boeing told CBS News.

"We do not discuss details of conversations we are having with customers, and our standard practice is to let customers announce any agreements that are reached. Any agreements reached will be contingent on US government approval."

Meanwhile, Boeing is nearing a $US4 billion deal with Russia's largest air-freight company – AirBridgeCargo Airlines and its Moscow-based parent, Volga-Dnepr Group – that would help extend the life of the 747 jumbo jet amid waning demand for four-engine aircraft, Bloomberg reported, citing people close to the transaction.

Further volatility ahead
In Europe, the Stoxx 600 Index ended the day with a surge of 3.7% from the previous close. The UK's FTSE 100 index added 3%, Germany's DAX index rose 3.4%, while France's CAC 40 index gained 3.5%.

The UK pound soared 2.3% against the US dollar to $US1.4688.

There is further volatility ahead.

"If I had a seatbelt while watching the markets, I'd put it on," Kim Forrest, senior equity research analyst at Fort Pitt Capital Group in Pittsburgh, told Reuters. "It's still a close call but this at least gives the markets a little bit of hope."

Before Thursday's referendum, investors will focus on US Federal Reserve chairwoman Janet Yellen, who is scheduled to give her semi-annual testimony before the Senate Banking Committee on Tuesday, and again before the House Financial Services Committee on Wednesday.

(BusinessDesk)