The iShares Morningstar Mid-Cap Growth ETF (JKH) was launched on 06/28/2004, and is a passively managed exchange traded fund designed to offer broad exposure to the Mid Cap Growth segment of the US equity market.The fund is sponsored by Blackrock. It has amassed assets over $275.60 M, making it one of the average sized ETFs attempting to match the Mid Cap Growth segment of the US equity market.Why Mid Cap GrowthMid cap companies have market capitalization between $2 billion and $10 billion. They usually have higher growth prospects than large cap companies and are less volatile than small cap companies. Thus they have a nice balance of growth potential and stability.Qualities of growth stocks include faster growth rates compared to the broader market, as well as higher valuations and higher than average sales and earnings growth rates. Also, growth stocks are a type of equity that carries more risk compared to others. When you consider growth versus value, growth stocks are usually the clear winner in strong bull markets but tend to fall flat in nearly all other environments.CostsSince cheaper funds tend to produce better results than more expensive funds, assuming all other factors remain equal, it is important for investors to pay attention to an ETF's expense ratio.Annual operating expenses for this ETF are 0.30%, putting it on par with most peer products in the space.It has a 12-month trailing dividend yield of 0.40%.Sector Exposure and Top HoldingsETFs offer a diversified exposure and thus minimize single stock risk but it is still important to delve into a fund's holdings before investing. Most ETFs are very transparent products and many disclose their holdings on a daily basis.This ETF has heaviest allocation to the Information Technology sector--about 31.70% of the portfolio. Healthcare and Industrials round out the top three.Looking at individual holdings, Servicenow Inc (NOW) accounts for about 1.56% of total assets, followed by Edwards Lifesciences Corp (EW) and Red Hat Inc (RHT).The top 10 holdings account for about 12.51% of total assets under management.Performance and RiskJKH seeks to match the performance of the Morningstar Mid Growth Index before fees and expenses. The Morningstar Mid Growth Index measures the performance of stocks issued by mid-capitalization companies. The Morningstar index methodology defines mid-capitalization stocks as those stocks that form the 20% of market capitalization between the 70th and 90th percentile of the market capitalization of the stocks eligible to be included in the Morningstar US Market Index.The ETF return is roughly 8.97% so far this year and was up about 20.14% in the last one year (as of 06/26/2018). In the past 52-week period, it has traded between $180.53 and $226.72.The ETF has a beta of 1.01 and standard deviation of 14.49% for the trailing three-year period, making it a medium risk choice in the space. With about 213 holdings, it effectively diversifies company-specific risk.AlternativesIShares Morningstar Mid-Cap Growth ETF holds a Zacks ETF Rank of 1 (Strong Buy), which is based on expected asset class return, expense ratio, and momentum, among other factors. Because of this, JKH is an outstanding option for investors seeking exposure to the Mid Cap ETFs segment of the market. There are other additional ETFs in the space that investors could consider as well.The iShares S&P Mid-Cap 400 Growth ETF (IJK) and the iShares Russell Mid-Cap Growth ETF (IWP) track a similar index. While iShares S&P Mid-Cap 400 Growth ETF has $8.06 B in assets, iShares Russell Mid-Cap Growth ETF has $8.80 B. IJK has an expense ratio of 0.25% and IWP charges 0.25%.Bottom-LinePassively managed ETFs are becoming increasingly popular with institutional as well as retail investors due to their low cost, transparency, flexibility and tax efficiency. They are excellent vehicles for long term investors.To learn more about this product and other ETFs, screen for products that match your investment objectives and read articles on latest developments in the ETF investing universe, please visit Zacks ETF Center.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 ISHARS-MO MC GR (JKH): ETF Research Reports ServiceNow, Inc. (NOW): Free Stock Analysis Report Red Hat, Inc. (RHT): Free Stock Analysis Report ISHARS-RS M GR (IWP): ETF Research Reports Edwards Lifesciences Corporation (EW): Free Stock Analysis Report ISHARS-SP MC GR (IJK): ETF Research Reports To read this article on Zacks.com click here.