Will SpaceX buy AST SpaceMobile stock? Should you?AST SpaceMobile (ASTS 2.44%) stock is on the move again Monday. Today's gain is about 2.3% as of 12:20 p.m., although the stock's bopping around quite a bit, and if you blink, it might just as easily go down as up.Credit for today's turbulence goes to Scotiabank analyst Andres Graham, who this morning lifted his price target on AST stock from $28 to$45.90 -- a very precise valuation on a stock that isn't particularly easy to value (because it has no profits ...