Thoubled electronics retailer RadioShack Corp's shares have lost nearly a third of their value since brokerage Wedbush Securities said on Tuesday the company could file for bankruptcy soon, making the stock worthless by the end of this year. The stock fell as much as 20 percent to 76 cents on Wednesday, adding to a 23 percent plunge on Tuesday. "Our price target reflects our expectation that creditors will force a reorganization and wipe out RadioShack's equity," Wedbush analyst Michael Pachter wrote in a note. Pachter, rated four stars out of five by StarMine for the accuracy of his calls on...