Take an appearance at some of the most significant movers in the premarket: GlaxoSmithKline (GSK)– The drugmakers stock increased 3.5% in the premarket after it detailed strategies to spin out its consumer health-care business into a different company. Glaxo will ultimately receive an $11 billion payment from the new company.MicroStrategy (MSTR)– MicroStrategy rallied 4.4% in premarket trading, trading in sync with the price of bitcoin. Shake Shack acquired 1.5% in premarket action.Winnebago (WGO)– The leisure automobile maker reported quarterly incomes of $2.16 per share, well above the consensus quote of $1.77 a share.