China's Market Crackdown Spooks Global Markets; Amex Slides

Stocks were under pressure Friday morning with Wall Street caught in the crossfire of a global market sell-off. News Chinese regulators will crack down on margin trading and expand the ability to short sell spooked international markets. In economic news, consumer prices were stable in March, adding 0.2%. That was unchanged from a month earlier and in line with expectations. American Express (AXP) shares were weighing on markets after the company reported quarterly revenue below estimates. Amex said weaker results were due to a stronger dollar and the loss of key partnerships, including its deal with Costco (COST).