Concerns about a slowdown of the Chinese economy sent the markets tumbling to a sharply lower close with the Dow plunging 125 points to 12,695. Nasdaq plummeted 31 points to 2902.

On the upside

Ventrus Biosciences (Nasdaq: VTUS) reported positive results from a late stage clinical trial of its anal fissure treatment diltiazem.

Shares of Horizon Pharma (Nasdaq: HZNP) continued rising after reporting a narrower first quarter loss last week.

Golf Town will pay a premium of approximately $96.5 million in cash to acquire Golfsmith International Holdings (Nasdaq: GOLF).

On the downside

Investors locked in profits on Melco Crown Entertainment (Nasdaq: MPEL), whose stock price rose last week after reporting higher first quarter results that beat analyst expectations.

First quarter earning rose for Silver Wheaton (NYSE: SLW) but the results fell short of expectations.

Iamgold (NYSE: IAG) disappointed with lower first quarter earnings and revenue.

In the broad market, declining issues outpaced advancers by a margin of more than 5 to 1 on the NYSE and by nearly 7 to 2 on Nasdaq. The Russell 2000 which tracks small cap stocks tumbled 11 points to 778.