Investors interested in Oils-Energy stocks should always be looking to find the best-performing companies in the group. Has APA (APA) been one of those stocks this year? Let's take a closer look at the stock's year-to-date performance to find out.APA is one of 255 individual stocks in the Oils-Energy sector. Collectively, these companies sit at #1 in 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. APA is currently sporting a Zacks Rank of #2 (Buy).Over the past three months, the Zacks Consensus Estimate for APA's full-year earnings has moved 26% higher. This is a sign of improving analyst sentiment and a positive earnings outlook trend.Based on the most recent data, APA has returned 83.2% so far this year. In comparison, Oils-Energy companies have returned an average of 31.6%. This shows that APA is outperforming its peers so far this year.Another Oils-Energy stock, which has outperformed the sector so far this year, is Antero Resources (AR). The stock has returned 233.6% year-to-date.The consensus estimate for Antero Resources' current year EPS has increased 8.6% over the past three months. The stock currently has a Zacks Rank #2 (Buy).To break things down more, APA belongs to the Oil and Gas - Exploration and Production - United States industry, a group that includes 43 individual companies and currently sits at #15 in the Zacks Industry Rank. On average, this group has gained an average of 100.9% so far this year, meaning that APA is slightly underperforming its industry in terms of year-to-date returns. Antero Resources is also part of the same industry.Going forward, investors interested in Oils-Energy stocks should continue to pay close attention to APA and Antero Resources as they could maintain their solid performance. 5 Stocks Set to Double Each was handpicked by a Zacks expert as the #1 favorite stock to gain +100% or more in 2021. Previous recommendations have soared +143.0%, +175.9%, +498.3% and +673.0%. Most of the stocks in this report are flying under Wall Street radar, which provides a great opportunity to get in on the ground floor.Today, See These 5 Potential Home Runs >>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 APA Corporation (APA): Free Stock Analysis Report Antero Resources Corporation (AR): Free Stock Analysis Report To read this article on Zacks.com click here.