The market is not really an indicator of the economy at large. Particularly since tRump cheated his was into office. It seems to over react violently to whatever he said last, whether positive or negative.
Which tweet caused yesterday’s decline and which tweet for today’s rise?
It's not necessarily tweets.
Yesterday's plunge was related to tRumps new tariffs and the fear of China's retaliation.
Today that retaliation failed to materialize in as bad a form as was feared so they bounce back.
Later this week or next week tRump will say "negotiations are going well" or "it's a bad bad thing what china is doing" and the markets will.surge one way or the other.
You do know tRump communicates in ways other than Twitter, right?