Terrorism fears sink stocks

Terrorism fears sent the markets tumbling during the midday with the Dow plummeting 151 points to 17,375. Nasdaq plunged 50 points to 4,688.

On the upside

Bargain hunters lifted shares of Paragon Shipping (Nasdaq: PRGN).

The International Journal of the Cardiovascular Academy published data from a pilot study using Cesca Therapeutics' (Nasdaq: KOOL) technology to treat acute myocardial infarction.

Spark Therapeutics (Nasdaq: ONCE) reported encouraging initial observations in a Phase 1/2 clinical trial of SPK-9001 to treat hemophilia B.

On the downside

Stage Stores (NYSE: SSI) widened first quarter losses as revenue fell prompting the retailer to cut its full year forecast.

Teekay (NYSE: TK) widened losses for the first quarter.

Teekay Tankers (NYSE: TNK) reported lower first quarter earnings that fell short of expectations.

In the broad market, declining issues outpaced advancers by a margin of more than 5 to 1 on the NYSE and by nearly 4 to 1 on Nasdaq. The broader S&P 500 tumbled 15 points to 2,031. Bitcoin dropped $5 to $448.