Designed to provide broad exposure to the Mid Cap Value segment of the US equity market, the Invesco S&P MidCap 400 Pure Value ETF (RFV - Free Report) is a passively managed exchange traded fund launched on 03/01/2006.The fund is sponsored by Invesco. It has amassed assets over $235.75 million, making it one of the average sized ETFs attempting to match the Mid Cap Value segment of the US equity market.Why Mid Cap ValueMid 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. They also have lower than average sales and earnings growth rates. When you look at long-term performance, value stocks have outperformed growth stocks in nearly all markets. Luckily, most ETFs are very transparent products that disclose their holdings on a daily basis.This ETF has heaviest allocation to the Financials sector--about 29.10% of the portfolio. In the past 52-week period, it has traded between $79.72 and $100.72.The ETF has a beta of 1.39 and standard deviation of 34.28% for the trailing three-year period, making it a high risk choice in the space. Investors might also want to consider some other ETF options in the space.The iShares Russell MidCap Value ETF (IWS - Free Report) and the Vanguard MidCap Value ETF (VOE - Free Report) track a similar index. While iShares Russell MidCap Value ETF has $13.03 billion in assets, Vanguard MidCap Value ETF has $15.92 billion.