Shares increased as much as 47% Thursday, continuing a huge rally over the past several days amid rumors that RadioShack could be in line for a cash infusion. The stock doubled this week and topped $1.50 on Thursday for the first time since June.    The stock is getting lift after a report earlier this week that shareholder Standard General could give RadioShack a rescue financing package. Standard General, which owns roughly 10% of RadioShack, is the same fund that recently gave the troubled retailer American Apparel Inc. a lifeline.

A rescue package could help the company pay down debt and ultimately close some underperforming stores, a decision that needs creditor approval.   Although the stock is up 135% this week alone,  it still remains down about 38% for the year.    Shares have been mired in a steep downtrend for years, fell below $1 in June and reached a low of 55 cents earlier this month.   By comparison, the stock traded above $20 as recently as late 2010 and peaked near $80 in 1999.