Wall Street moved higher overnight, bolstered by gains in Apple shares after Warren Buffett's Berkshire Hathaway disclosed that it owns a stake worth about US$1.1 billion in the iPhone maker. Oil also helped underpin the mood.
In 2.53pm New York trading, the Dow Jones Industrial Average rallied 1.1 percent, while the Nasdaq Composite Index climbed 1.5 percent. In 2.38pm trading, the Standard & Poor's 500 Index gained 1.1 percent.
Gains in shares of Apple and those of Home Depot, recently trading 4 percent and 2.3 percent stronger respectively, led the Dow higher.
Berkshire held 9.81 million Apple shares as of March 31, according to a regulatory filing.
Apple stock "is stunningly cheap, and it has a massive pile of cash," Steve Wallman, founder of Wallman Investment Counsel in Middleton, Wisconsin, who has owned Berkshire since 1982 and Apple since 2003, told Reuters. "Apple is not getting credit for research and development it is doing behind the scenes."
Equities also received a lift from oil, which advanced more than 2 percent. Goldman Sachs became more upbeat about the outlook, predicting US crude might rise as high a US$50 a barrel in the second half of this year.
"The oil market has gone from nearing storage saturation to being in deficit much earlier than we expected," said Goldman, which added that supply likely shifted into a deficit in May, Reuters reported.
It helped the mood.
"Earnings are over more or less and the market is searching to see what the second half of the year will look like," Craig Sterling, head of US equity research at Pioneer Investments in Boston, told Bloomberg. "The price of oil and other commodities seem to be catching a bid so there's hope there will be improvement in the industrial side of the economy."
Meanwhile, shares of Pfizer rose, trading 0.5 percent higher as of 2.50pm in New York, after the company said it agreed to buy Anacor Pharmaceuticals in a deal worth about US$5.2 billion. Shares of Anacor soared 55.7 percent.
"We believe the acquisition of Anacor represents an attractive opportunity to address a significant unmet medical need for a large patient population with mild-to-moderate atopic dermatitis, which currently has few safe topical treatments available," Albert Bourla, group president of Pfizer's Global Innovative Pharma and Global Vaccines, Oncology and Consumer Healthcare Businesses, said in a statement.
"Anacor will be a strong fit with Pfizer's innovative business, further supporting our strategic focus on Inflammation and Immunology, and is expected to enhance near-term revenue growth for the innovative business," he said.
Europe's Stoxx 600 Index finished the day with a gain of less than 0.1 percent from previous close. The UK's FTSE 100 index added 0.2 percent. France's CAC 40 index slipped 0.2 percent. German financial markets were closed for a holiday.