What happened CarMax (NYSE: KMX) shareholders beat a rallying market last month. Their stock rose 11% in March compared to a 4.2% increase in the S&P 500, according to data provided by S&P Global Market Intelligence. The rally added to significant gains for the used car retailer, with shares up over 30% so far in 2021. Image source: Getty Images. So what Plunging COVID-19 case rates combined with encouraging economic news to brighten investors' outlook for CarMax's business last month. But the main factor pulling shares higher was expectations for a strong earnings report in early April. Federal stimulus efforts put more cash into consumers' pockets, and that usually means good things for the nation's leading used car retailer. Now what CarMax said in early April that sales indeed were lifted by the second round of stimulus payments. However, those gains were offset by severe winter weather in February. The chain also endured inventory challenges related to COVID-19 that kept a lid on revenue growth. Overall, automotive sales volumes were essentially flat in the fourth quarter. That growth figure should improve as CarMax works through its inventory problems and as warmer weather makes its lots more accessible this spring. Meanwhile, management is continuing its bid to make the car buying process e-commerce friendly by acquiring the Edmunds research platform. 10 stocks we like better than CarMaxWhen 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 CarMax 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 Demitri Kalogeropoulos has no position in any of the stocks mentioned. The Motley Fool recommends CarMax. The Motley Fool has a disclosure policy.Source