The hydrogen stock is now down more than 60% year to date.Plug Power (PLUG 5.44%) has been in freefall in recent months, with the hydrogen stock losing another 23.9% value in August, according to data provided by S&P Global Market Intelligence. Plug Power stock is now down a whopping 40% in just three months. What's going on here, and is there any hope left for investors?Plug Power's biggest problemsPlug Power might be a frontrunner in green hydrogen, but the company is incurring huge losses, burning cash r ...