Is AST stock burning through its cash too fast?Shares of satellite telecommunications company AST SpaceMobile (ASTS -4.16%) rose 15% through 10 a.m. ET Friday morning after yet another Wall Street analyst hiked its price target. By 11 a.m., though, the stock had turned tail and plunged 8.5%.Why the pop and why the drop? TheFly.com notes Scotiabank analyst Andres Coello raised his target on AST to $28 today. That sounds like good news, and Coello insists the stock will outperform. Problem is, AST stock alrea ...