Some key events coming up

The ECB will probably hold rates on Thursday but indicate that downside risks have intensified, suggesting further easing is possible before year-end.

U.S. CPI data is due Friday, with consumer prices expected to rise in August for a third straight month.

These are the main moves in markets:

Stocks

The S&P 500 Index dipped 2.8% to 3,331 as of 4 p.m. New York time, the lowest in four weeks.

The Dow Jones Industrial Average decreased 2.3%.

The Nasdaq Composite Index declined 4.1%, the lowest in four weeks.

The Nasdaq 100 Index fell 4.8%.

Currencies

The Bloomberg Dollar Spot Index gained 0.5% to the highest in more than two weeks.

The euro dipped 0.3% to $1.1778, reaching the weakest in four weeks on its sixth consecutive decline.

The Japanese yen appreciated 0.2% to 106.07 per dollar, the strongest in a week on the largest gain in more than a week.

Bonds

The yield on two-year Treasuries dipped less than one basis point to 0.14%.

The yield on 10-year Treasuries dipped four basis points to 0.68%, the largest decrease in five weeks.

The yield on 30-year Treasuries dipped five basis points to 1.42%, the biggest dip in almost seven weeks.

Commodities

West Texas Intermediate crude sank 7.3% to $36.89 a barrel, the lowest in 14 weeks on the largest tumble in 20 weeks.

Gold strengthened 0.1% to $1,936.42 an ounce.

Copper dipped 1.3% to $3.02 a pound.