Stocks could be facing the end-of-quarter reckoning many investors feared when Elon Musk’s SpaceX unveiled plans for its multibillion-dollar initial public offering and Federal Reserve Chairman Kevin Warsh took over the central bank’s policy reigns earlier this month. The early signs of a late June “tech wreck” started to formulate Monday, with Google parent Alphabet shedding more than $225 billion in market value, its biggest slump in more than a year, and SpaceX extending its three-day decline to more than $600 billion. Shares in SpaceX were falling 4.3% in premarket trading Tuesday, putting them below $150 a share.