What happened Shares of FuelCell Energy (NASDAQ: FCEL) jumped as much as 20.8% in trading Thursday after getting a notable upgrade from an analyst. The stock held double-digit gains most of the day and was up 12.3% at 1 p.m. EDT. So what J.P. Morgan analyst Paul Coster initiated coverage on FuelCell Energy stock with an overweight rating and a $3 price target. The price implies a nearly 40% upside from yesterday's closing price. Image source: Getty Images. Coster thinks that improvements on the balance sheet and the business moving toward profitability will help the stock over the next year. It doesn't hurt that clean energy and hydrogen have been favorites among investors over the last few months. That's helping push shares higher, even if FuelCell Energy still hasn't reached profitability. Now what The upgrade in shares has caused a temporary bounce in FuelCell Energy's stock, but the long-term challenges haven't changed. As you can see below, the company is losing money and funding continuing operations by issuing more and more shares to investors. FCEL data by YCharts This isn't currently a sustainable business model, and until we see FuelCell Energy turn around operations, I will focus my investing dollars on more sustainable renewable energy stocks. 10 stocks we like better than FuelCell EnergyWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and FuelCell Energy wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of September 24, 2020 Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source