Summary: Here's everything you need to know before Tuesday's opening bell: Amazon confirmed hundreds of corporate layoffs. AmerisourceBergen gained premarket on reports that Walgreens may buy the portion it doesn't already own. GM will shutdown an underutilized plant in South Korea. Barnes & Noble is reportedly laying off lead cashiers, digital leads and other experienced workers. U.S. stock futures were under pressure following Monday's strong gains. Subscribe to TheStreet on Youtube and enjoy these Editor Picks!
