Pushed by yesterday’s marketwide slump, Barnes & Noble’s stock is now trading at levels that the company it’s lowest market capitalization in at least a decade, if not longer. This morning shares opened at $7.30 and were down slightly again, for a market cap of about $510 million. The stock had dipped to about $8.25 a share in early 2016, and the last big dip was in March 2011, when the price dropped a little below $9 a share — but there were fewer common shares outstanding then, since Liberty Media still held separate preferred shares at time. [Update/correx: There were fewer common […]