While it's unclear, so far, whether the S&P 500 will succeed in staving off a losing week, there's little doubt that hydrogen stocks will end up significantly lower than before trading began on Monday morning. Between shareholders fearing dilution and the prospect of increased competition, several factors have motivated investors to click the sell button this week. According to data provided by S&P Global Market Intelligence, Plug Power (PLUG 3.93%) stock plummeted 30% from the end of trading last Friday th ...