Georgia Gulf ( GGC), a maker of chlorovinyl products used in building and home improvement products, saw its shares soar 38 cents, or 29% to $1.68 Wednesday after an analyst upgrade. BB&T Capital Markets upgraded the Atlanta-based company from underweight to hold. More than 2.3 million shares traded on Wednesday. On Tuesday, the company announced that it has entered into an amendment to its senior secured credit facility to reset covenants until March 2010 with its lenders and that it has increased and extended its accounts receivable securitization until March 2011. "This amendment provides additional flexibility to improve our capital structure and strengthens Georgia Gulf's position in these challenging economic conditions," said Paul Carrico, president and CEO of Georgia Gulf. Shares of shoemaker Crocs ( CROX) dropped 27 cents, or 19% to $1.14 after a 10-K filing with the Securities and Exchange Commission Tuesday said that accounting firm Deloitte & Touche raised questions about the company's ability to function as a going concern, citing "the maturity of the company's revolving credit facility on April 2 and losses from operations." Restaurant chain Ruby Tuesday ( RT) rose 22.5%, or 44 cents to $2.40. Last week, the Maryville, Tenn.-based operator of Ruby Tuesday restrauants said it would continue to expand in the Middle East under a new franchise agreement with Global Brands Qatar. Global Brands Qatar plans to develop and operate three Ruby Tuesdays in the city of Doha and elsewhere in Qatar over the next five years. Modine Manufacturing ( MOD) shares rose 25.2%, or 32 cents to $1.59. The Racine, Wis.-based maker of thermal management products named Scott L. Bowser as regional vice president for the Americas.