Major U.S. indexes falling more than one percent on investor concerns over a clamp-down on margin trading in China and a lot of disappointing earnings results from U.S. corporations. Chinese authorities lifted restrictions on short-selling while also warning against excessive borrowing on margin, two developments that could pressure that market.

Almost all of the Dow stocks are trading in negative area (29 of 30). Top looser - American Express Company (AXP,-4.75%). Top gainer - General Electric Company (GE, +0.34%).

S&P index sectors are moving down. Top looser - Utilities (-0.6%).

At the moment:

Dow 18038.00 +16.00 +0.09%

S&P 500 2099.25 -0.50 -0.02%

Nasdaq 100 4413.00 -8.75 -0.20%

10-year yield 1.92% +0.02

Oil 56.08 -0.31 -0.55%

Gold 1196.80 -4.50 -0.37%