Recovering from yesterday's growth stock sell-off, shares of hydrogen fuel cell companies Plug Power (NASDAQ: PLUG) and Bloom Energy (NYSE: BE) -- both of which both produce fuel cell systems and are building hydrogen production businesses to fuel those cells -- and also Nikola Corporation (NASDAQ: NKLA), which is building fuel cell-powered trucks, bounced back in Friday trading. As of noon ET, Plug stock is up 7.7% and Bloom is gaining 5.2%, and both of these stocks are trading above where they were before yesterday's sell-off. Nikola isn't quite back to where it was pre-sell-off, but it's close -- and it's up 6.5% today.