As we had reported on Friday, Barnes & Noble’s poor holiday sales and reduced earnings guidance drove the bookseller’s shares over 13 percent to new all-time lows, closing at $5.60 a share. In early Tuesday trading, shares were pushed down further, to approximately $5.125 a share, down another 7 percent or more for the day so far. That brings the bookseller’s market cap down to about $370 million.