Plug Power Inc (NASDAQ:PLUG) shares fell sharply Friday after President Donald Trump formally nominated former Fed governor Kevin Warsh as Federal Reserve chair, sparking fears that a more hawkish policy regime and potentially higher-for-longer interest rates could squeeze the hydrogen fuel-cell maker's capital-intensive growth plans.Here’s what investors need to know.Plug Power stock is feeling bearish pressure. Why are PLUG shares down?Why Trump’s Fed Chair Pick MattersAt the same time, if tighter Fed pol ...