Zacks Investment Research is a prominent American research and investment services provider. It is known for its extensive coverage of stocks, mutual funds and exchange-traded funds (ETFs). Founded in 1978 by Len Zacks, a PhD scholar from MIT, Zacks is renowned for producing high-quality independent research and commentary.

At the heart of Zacks is its proprietary "Zacks Ranks" system. This is a stock rating system on a scale from one to five, with #1 being the highest and strongest buy recommendation. As Len Zacks described, the revision of earnings estimates is the "most powerful force impacting stock prices" and the Zacks Ranks system takes this into account in its stock ratings.

In recent years, Zacks has expanded its offering further with ratings for mutual funds and ETFs. This system is incredibly useful for investors because it helps them to make informed decisions about their portfolios. Most of Zacks' ratings also feature a ‘recommendation percentile’ – which tells investors where a given stock or fund ranks among its peers. For example, a fund with a recommendation percentile of 90th has a better outlook than one with a percentile of 25th.

The company also offers comprehensive analyst reports that provide in-depth analysis on more than 4,500 stocks. Designed with both institutional and individual investors in mind, these reports offer a detail summary of different stocks, along with the Zacks Rank for each security.

In addition, Zacks provides services to a wide range of customers – including hedge funds, banks, mutual funds, pension plans, and financial advisors. The firm also has its own ETF, the Zacks Investment Research Income ETF (ZIRC). This is structured as a fund of funds, meaning that investors get exposure to seven different ETFs, allowing them to gain exposure to both domestic and international securities and maximize their investment potential.

All in all, Zacks Investment Research offers comprehensive research and analysis services for investors to make informed decisions. With its proprietary Zacks Ranks system, comprehensive analyst reports, and the Zacks Investment Research Income ETF, it covers the full spectrum of investment types. In short, Zacks makes finding and investing in the markets easier and more profitable.