Have you been paying attention to shares of AutoNation (AN)? Shares have been on the move with the stock up 11.6% over the past month. The stock hit a new 52-week high of $127.22 in the previous session. AutoNation has gained 80% since the start of the year compared to the -5.4% move for the Zacks Retail-Wholesale sector and the 40.5% return for the Zacks Automotive - Retail and Whole Sales industry.What's Driving the Outperformance?The stock has a great record of positive earnings surprises, as it hasn't missed our earnings consensus estimate in any of the last four quarters. In its last earnings report on July 19, 2021, AutoNation reported EPS of $4.83 versus consensus estimate of $2.85 while it beat the consensus revenue estimate by 17.54%.For the current fiscal year, AutoNation is expected to post earnings of $15.32 per share on $25.58 billion in revenues. This represents a 115.17% change in EPS on a 25.44% change in revenues. For the next fiscal year, the company is expected to earn $12.72 per share on $25.7 billion in revenues. This represents a year-over-year change of -16.99% and 0.49%, respectively.Valuation MetricsAutoNation may be at a 52-week high right now, but what might the future hold for the stock? A key aspect of this question is taking a look at valuation metrics in order to determine if the company is due for a pullback from this level.On this front, we can look at the Zacks Style Scores, as these give investors a variety of ways to comb through stocks (beyond looking at the Zacks Rank of a security). These styles are represented by grades running from A to F in the categories of Value, Growth, and Momentum, while there is a combined VGM Score as well. Investors should consider the style scores a valuable tool that can help you to pick the most appropriate Zacks Rank stocks based on their individual investment style.AutoNation has a Value Score of A. The stock's Growth and Momentum Scores are A and C, respectively, giving the company a VGM Score of A.In terms of its value breakdown, the stock currently trades at 8.2X current fiscal year EPS estimates. On a trailing cash flow basis, the stock currently trades at 9.6X versus its peer group's average of 9.2X. Additionally, the stock has a PEG ratio of 0.43. This isn't enough to put the company in the top echelon of all stocks we cover from a value perspective.Zacks RankWe also need to consider the stock's Zacks Rank, as this supersedes any trend on the style score front. Fortunately, AutoNation currently has a Zacks Rank of #1 (Strong Buy) thanks to rising earnings estimates.Since we recommend that investors select stocks carrying Zacks Rank of 1 (Strong Buy) or 2 (Buy) and Style Scores of A or B, it looks as if AutoNation fits the bill. Thus, it seems as though AutoNation shares could still be poised for more gains ahead. More Stock News: This Is Bigger than the iPhone! It could become the mother of all technological revolutions. Apple sold a mere 1 billion iPhones in 10 years but a new breakthrough is expected to generate more than 77 billion devices by 2025, creating a $1.3 trillion market. Zacks has just released a Special Report that spotlights this fast-emerging phenomenon and 4 tickers for taking advantage of it. If you don't buy now, you may kick yourself in 2022.Click here for the 4 trades >>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 AutoNation, Inc. (AN): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research