Stock markets

KEEPING SCORE: The Dow Jones industrial average lost 357 points, or 2.1 percent, to 16,177 as of 10:02 a.m. Eastern time. The Standard & Poor's 500 index lost 41 points, or 2.1 percent, to 1,931 and the Nasdaq composite fell 83 points, or 2.8 percent, to 4,691.

Investors have been gripped by an increasing sense of unease this week, largely because of the uncertainty related to China. Since early summer, Chinese stocks have taken a battering but global markets haven't responded much — until now.

Following last week's decision by the country's monetary authorities to reduce the value of the yuan, China's currency, stock markets have really taken a hit.