Even with record levels of hydrogen fuel production, Plug Power stock still can't earn a profit. ET, Plug stock has gone essentially full circle -- back at only a 1% gain. Plug throws a partyBut why did Plug Power stock explode higher today in the first place? Is Plug stock a buy? With a $3 billion market capitalization and annual losses of nearly $2 billion, Plug stock still looks like a sell to me.