Shares of Plug Power (PLUG -4.46%) jumped this week, up from last Thursday's close at 1 p.m. ET for the Fourth of July holiday by 17.5% as of 12:30 p.m. ET Friday. The spike comes as the S&P 500 (^GSPC -0.25%) and Nasdaq-100 were both up 0.5%.The company, which develops clean hydrogen power, announced earlier this week that it secured a critical new contract that will improve cash flows, something the struggling company desperately needs.Plug Power has negotiated a new dealThe multiyear extension to its con ...