Yahoo’s second-quarter earnings jumped 51 percent, but the Internet giant spooked investors with third-quarter guidance that fell short of Wall Street expectations, notes Dow Jones Newswires. Yahoo said revenue for the third quarter is expected to be in the range of US$1.57 billion to US$1.65 billion, the midpoint of which is below the average analyst forecast of US$1.64 billion. Shares in Yahoo were down 6.3 percent at US$14.24 in after-hours trading.