•Companies

Amgen stock surges: Amgen Inc. rose the most in four years in New York trading after the company reported its lead experimental product, a bone- strengthening medicine, worked better than a potential rival in a study.

Shares of Thousand Oaks, Calif.-based Amgen surged $7.27, or 14 percent, to $59.50 at 4 p.m. in Nasdaq Stock Market composite trading, the most since July 20, 2005, a day after the company reported a 38- percent jump in quarterly profit. Study results for the drug, called denosumab, were announced yesterday after the market closed.

Denosumab did a better job in the clinical trial than Novartis AG’s Zometa delaying fractures and other complications in breast cancer patients whose illness had spread to their bones, Amgen said. Analysts raised peak annual revenue projections for the drug and price expectations for Amgen stock.

“Superior efficacy could enable denosumab to establish a new standard of care,” said Ian Somaiya, an analyst with Thomas Weisel Partners LLC in New York, in a note to clients Wednesday.

Amgen has a biomanufacturing plant in West Greenwich. (Bloomberg News)

Buffett lunch: A Canadian investment firm paid $1.68 million in last month’s charity auction to win lunch with billionaire investor Warren Buffett.

The Glide Foundation, which receives all the auction proceeds, said Wednesday that Salida Capital, which is based in Toronto, won the auction.

Salida Capital CEO Courtenay Wolfe says the auction offered a unique opportunity to sit down with one of the world’s greatest investors.

Buffett annually auctions off a lunch to benefit Glide, which provides social services to San Francisco’s homeless and poor.

Salida Capital will be able to send a total of eight people for the lunch with Berkshire’s chairman and chief executive. The owners of the Smith & Wollensky restaurant in New York contributed $10,000 to Glide and will again host the lunch.

Wolfe said he plans to bring along a handful of his firm’s biggest supporters. Salida Capital is marking its tenth anniversary this year, and Wolfe said it has recovered well from last year’s difficult market, so the time seemed right to bid. (Associated Press)

•Markets

Dollar mixed: The dollar was mixed against major currencies yesterday in New York, ending at 92.45 Japanese yen, down from Tuesday’s close of 94.81 yen. The euro closed at 3:30 p.m. at $1.3851, down from $1.3927.

Metals fall: Gold for current delivery closed at $909 a troy ounce on the New York Mercantile Exchange, down from Tuesday’s close of $928.80. Silver closed at $12.841 an ounce, down from $13.209.

Fuels drop: August light, sweet crude oil fell $2.79, to $60.14 a barrel on the New York Mercantile Exchange. August gasoline slid 9.9 cents to $1.6333 a gallon. August heating oil lost about 6.3 cents to $1.5379 a gallon. August natural gas fell 7.6 cents to settle at $3.353 per 1,000 cubic feet.— Associated Press