SpaceX's mega rally is hitting its first stumble

SpaceX executives celebrate the company's record-breaking IPO on Friday.TIMOTHY A. CLARY / AFP via Getty ImagesSpaceX has broken its post-IPO streak.Shares in Elon Musk's rocket company were down nearly 5% at market close on Wednesday.The slide continued on Thursday, but shares are still up 31% from the IPO price.SpaceX's post-IPO mega-rally has hit its first slowdown.Shares in Elon Musk's rocket company, which raised a record $75 billion when it went public last week, had dropped nearly 5% on m