Concerns about a potential military offensive in Syria sank the markets with the Dow crashing 218 points to 24,189. Nasdaq fell 25 points to 7069.

On the upside

Pretium Resources (NYSE: PVG) reported first quarter production results and provided an operations update for the Brucejack Mine.

Stifel Nicolaus upgraded AeroVironment (Nasdaq: AVAV) from a Hold rating to a Buy rating and lifted its price target from $45.00 to $65.00.

Rosenblatt Securities expects Applied Optoelectronics (Nasdaq: AAOI) to rebound this quarter.

On the downside

Kerrisdale Capital wrote that it was shorting QuinStreet (Nasdaq: QNST) due to the company's outdated business model.

Analogic (Nasdaq: ALOG) will be taken private by an affiliate of Altaris Capital Partners for a discounted price of $84.00 per share in cash.

Profit taking weighed down shares of CarGurus (Nasdaq: CARG).

In the broad market, advancing issues were on par with decliners on the NYSE while decliners barely edged out advancers by a slim margin on Nasdaq. The broader S&P 500 fell 14 points to 2,642. Bitcoin gained $49 to $6,911.