Investors interested in Retail-Wholesale stocks should always be looking to find the best-performing companies in the group. Has CarMax (KMX) been one of those stocks this year? Let's take a closer look at the stock's year-to-date performance to find out.CarMax is one of 211 companies in the Retail-Wholesale group. The Retail-Wholesale group currently sits at #1 within the Zacks Sector Rank. The Zacks Sector Rank considers 16 different groups, measuring the average Zacks Rank of the individual stocks within the sector to gauge the strength of each group.The Zacks Rank emphasizes earnings estimates and estimate revisions to find stocks with improving earnings outlooks. This system has a long record of success, and these stocks tend to be on track to beat the market over the next one to three months. KMX is currently sporting a Zacks Rank of #1 (Strong Buy).The Zacks Consensus Estimate for KMX's full-year earnings has moved 14.06% higher within the past quarter. This signals that analyst sentiment is improving and the stock's earnings outlook is more positive.Based on the latest available data, KMX has gained about 42.26% so far this year. Meanwhile, the Retail-Wholesale sector has returned an average of -1.07% on a year-to-date basis. This means that CarMax is performing better than its sector in terms of year-to-date returns.To break things down more, KMX belongs to the Automotive - Retail and Wholesale - Parts industry, a group that includes 4 individual companies and currently sits at #18 in the Zacks Industry Rank. Stocks in this group have gained about 34.08% so far this year, so KMX is performing better this group in terms of year-to-date returns.Investors with an interest in Retail-Wholesale stocks should continue to track KMX. The stock will be looking to continue its solid performance. Breakout Biotech Stocks with Triple-Digit Profit Potential The biotech sector is projected to surge beyond $775 billion by 2024 as scientists develop treatments for thousands of diseases. They’re also finding ways to edit the human genome to literally erase our vulnerability to these diseases. Zacks has just released Century of Biology: 7 Biotech Stocks to Buy Right Now to help investors profit from 7 stocks poised for outperformance. Our recent biotech recommendations have produced gains of +50%, +83% and +164% in as little as 2 months. The stocks in this report could perform even better.See these 7 breakthrough stocks now>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report CarMax, Inc. (KMX): Free Stock Analysis Report To read this article on Zacks.com click here.