What happened Shares of Aemetis (NASDAQ: AMTX) were higher by roughly 17% at 1 p.m. EDT. The renewable fuels and biochemicals company didn't release any specific news today that would have elicited such a dramatic rise in price. But a Credit Suisse analyst did. So what Manav Gupta of Credit Suisse started coverage of Aemetis with an outperform rating. The stock was given a price target of $35 per share, which is roughly 75% above where the stock closed on March 19, the previous trading day. Investors often buy a stock when it is added to coverage with a favorable rating. The lofty price target probably didn't hurt, either. Image source: Getty Images. Gupta said Aemetis will benefit materially as the world moves toward a lower carbon future. Specifically, the analyst expects the company to be levered to renewable natural gas growth. Also highlighted was the company's efforts to develop renewable jet and diesel fuels. Clean energy is a hot topic today, so it's not surprising that investors jumped on the analyst update here and bought the stock. Now what There is clearly a huge amount of opportunity as the world tries to find ways to reduce its carbon footprint. Aemetis may or may not end up a big winner. That said, investors have been treated to a massive 3,100% price advance over the past year. In other words, a lot of good news is already priced in. Long-term investors should probably tread with care. Despite the exciting opportunities Credit Suisse is highlighting, stocks that go up impressively sometimes reverse course just as dramatically. 10 stocks we like better than AemetisWhen 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 Aemetis 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 February 24, 2021 Reuben Gregg Brewer 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