Investors interested in Business Services stocks should always be looking to find the best-performing companies in the group. Has ABM Industries (ABM) been one of those stocks this year? Let's take a closer look at the stock's year-to-date performance to find out.ABM Industries is one of 278 individual stocks in the Business Services sector. Collectively, these companies sit at #4 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. ABM Industries is currently sporting a Zacks Rank of #2 (Buy).Over the past three months, the Zacks Consensus Estimate for ABM's full-year earnings has moved 6.4% higher. This is a sign of improving analyst sentiment and a positive earnings outlook trend.Based on the most recent data, ABM has returned 25.2% so far this year. In comparison, Business Services companies have returned an average of -21.7%. This shows that ABM Industries is outperforming its peers so far this year.Another Business Services stock, which has outperformed the sector so far this year, is BGSF (BGSF). The stock has returned 8.8% year-to-date.The consensus estimate for BGSF's current year EPS has increased 0.8% over the past three months. The stock currently has a Zacks Rank #2 (Buy).To break things down more, ABM Industries belongs to the Building Products - Maintenance Service industry, a group that includes 4 individual companies and currently sits at #104 in the Zacks Industry Rank. On average, this group has lost an average of 5.8% so far this year, meaning that ABM is performing better in terms of year-to-date returns.On the other hand, BGSF belongs to the Business - Services industry. This 29-stock industry is currently ranked #82. The industry has moved +141.6% year to date.ABM Industries and BGSF could continue their solid performance, so investors interested in Business Services stocks should continue to pay close attention to these stocks. 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 ABM Industries Incorporated (ABM): Free Stock Analysis Report BGSF, Inc. (BGSF): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research