Despite upbeat economic data, the markets opened sharply lower with the Dow collapsing 170 points to 16,150 over concerns of a potential war in Ukraine. Nasdaq plunged 51 points to 4257.

On the upside

Reports that Indonesia may lower mineral concentrates export tax lifted shares of Newmont Mining (NYSE: NEM).

Dendreon (Nasdaq: DNDN) widened losses for the fourth quarter but the results were better than expected.

xG Technology (Nasdaq: XGTI) received a patent for cognitive radios.

On the downside

Darden Restaurants (NYSE: DRI) forecast third quarter earnings well below analyst expectations due to severe weather conditions.

Russia's invasion of Ukraine sent shares of Mobile Telesystems (NYSE: MBT) and Yandex (Nasdaq: YNDX) tumbling.

Akorn (Nasdaq: AKRX) reported higher fourth quarter earnings and revenue but the company forecast 2014 results below expectations.

In the broad market, declining issues outpaced advancers by a margin of nearly 3 to 1 on the NYSE and by more than 3 to 1 on Nasdaq. The broader S&P 500 tumbled 17 points to 1842. Bitcoin gained $49.18 or 8.90% to $601.64.