One formerly high-flying alternative energy stock just got a surprising vote of confidence — here’s what the latest numbers reveal.Connecticut-based Manatuck Hill Partners disclosed the purchase of 2.5 million shares of Plug Power Inc. (PLUG), resulting in a post-trade position valued at approximately $5.9 million per a November 14 SEC filing.What HappenedAccording to a filing with the Securities and Exchange Commission dated November 14, Manatuck Hill Partners, LLC acquired 2.5 million additional shares of ...