Amazon Surge, Apple Plunge as Oil Prices Fuel Inflation Worries

The US stock market was volatile on Friday, swinging between gains and losses. Amazon's strong profit report led to a 15% surge in its shares, but Apple's disappointing forecast caused its stock to drop by 9.2%. Rising oil prices also added to worries about inflation.

Rising oil prices pushed the cost of regular gasoline to an average of nearly $4.11 per gallon across the US, up from $3.85 a month ago, according to AAA. This has put upward pressure on prices for virtually every product that rides on a ship, plane or truck before it gets to a customer.

The yield on the 10-year Treasury jumped to 4.73% from 4.68% late Thursday, and Federal Reserve Chair Kevin Warsh's promise to get inflation back down to 2% has not alleviated concerns about interest rates. The Fed voted again to keep its main interest rate steady on Wednesday, even though inflation continues to remain well above 2%. Warsh has been criticized for not providing clear guidance on future interest rate decisions.