Zacks Earnings Small-Cap US Index aims to generally track the performance of stocks that have a market capitalization ranking in the range of 1001 to 3000. The Index also strives to outperform the comparable universe on both a market-capitalization weighted and equally-weighted basis. In its effort to deliver outperformance, Zacks relies upon two proprietary investment factors - Zacks Rank and Zacks Quality. The Zacks Rank factor focuses on Earnings Estimate Revision information, while the Zacks Quality factor focuses on Earnings Quality information.