What happened Shares of electric commercial truck start-up Nikola (NASDAQ: NKLA) have been bouncing around this week. After jumping Tuesday, the stock reversed course today. Shares were trading down 6.5% as of 2:20 p.m. EDT. So what The volatility comes as the concept of hydrogen fuel cell electric vehicles is getting more press. Yesterday, an announcement from Korean automaker Hyundai on the topic was widely reported by CNBC. Nikola has been developing both battery electric and hydrogen fuel cell electric semitrucks and plans to have its first one commercially available by the end of the year. Image source: Nikola. Reports that a major automaker plans to have all of its vehicle models available with hydrogen fuel cell power by 2028 potentially helps to support Nikola's business strategy. But it also brings competition that might explain why shares reversed direction today, giving up all of yesterday's gains and more. Now what Hyundai also collaborates with Canada-based Hydrogen Technology & Energy Corporation, which was also in the news today regarding hydrogen fuel cell electric vehicles. HTEC announced a $170 million investment that will help it "to develop new low-carbon hydrogen projects and to increase its network of stations supporting cars and heavy vehicles." The investment by industrial gas and technology equipment company Chart Industries (NYSE: GTLS) grows Chart's stake in HTEC to 25% ownership. The deal also gives Chart preferential rights to increase ownership should another investing partner decide to sell its stake in the future. As mentioned, the expanding growth of the hydrogen economy could be seen as both positive and negative for Nikola. Winners and losers won't be filtered out until much further into the life cycle. For today, it seems more investors are thinking increasing competition is a net negative for Nikola's future potential. 10 stocks we like better than Nikola CorporationWhen our award-winning analyst team has 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.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Nikola Corporation 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 August 9, 2021 Howard Smith owns shares of Nikola Corporation. The Motley Fool owns shares of and recommends Chart Industries. The Motley Fool has a disclosure policy.Source