Investors will remain on edge Thursday, amid rising tensions in Ukraine and ahead of testimony by the Federal Reserve Chairman Janet Yellen. In a challenge to Ukraine`s new leaders , dozens of armed men seized the regional government administration building and parliament in Ukraine`s southern Crimea region Thursday and raised the Russian flag. That followed surprise military exercises by Russia on Ukraine`s doorstep Wednesday. Stock futures pedaled back Thursday morning on reports of rising military tension, as risk appetite has been hit by the latest developments. -Futures on the Dow Jones Industrial Average lost 0.291% to 16131 -Futures on the S&P 500 index lost 0.293% to 1836.50 -Futures on the NASDAQ 100 lost 0.129% to 3669.00. As of 07:11 a.m. ET U.S. stocks closed little changed Wednesday. After coming in sight of another record high, the S&P 500 rose less than a point for the day. The Dow Jones Industrial Average and the NASDAQ rose just a handful of points each. Also on the economic front, the U.S. government will release its weekly report on initial jobless claims and its monthly report on durable goods orders, both at 8:30 a.m. ET. Yellen Testimony Investors globally are waiting testimony fro the Federal Reserve Chief, anticipating any new clues about future monetary policy. Yellen, 67, who recently took on the role as head of the Fed, will testify before the Senate Banking Committee at 10:00 a.m. ET, and her comments should create an impact on markets. Yellen was originally scheduled to speak two weeks ago when she also testified before the House , but her appearance was delayed due to bad weather. Corporate News Plenty of stocks were on the move ahead of the opening bell. Shares in J.C. Penney look set to soar by more than 15% when the markets open. The retailer reported a narrower-than-expected loss for the fourth quarter after the close Wednesday, and said it expects same-store sales to rise by 3% to 5% during the current quarter. Tesla stock is also getting a boost Thursday morning after the automaker announced it was raising $1.6 billion to fund its expansion plans. Shares in the Chinese search engine Baidu were rising in premarket trading after the company posted solid earnings and sales. Meanwhile, investors are awaiting quarterly earnings before the opening bell from the likes of Best Buy and Kohl`s. Salesforce.com and Gap will report after the close.