Stocks that fall within the mid-cap range provide unique opportunities to investors seeking growth on capital over the long term. Unlike large-cap stocks that provide stability due to strong historical earnings and an established reputation among consumers, mid-cap companies are often lesser known but with higher growth potential and therefore additional volatility. However, mid-cap company stocks offer more stability than small-cap equities as it relates to price volatility. Mid-cap stocks can be a strong complement to both large- and small-cap stocks within a portfolio for investors who are willing to take on more risk for the potential of greater returns.

While mid-cap stocks have their merits, not all mid-cap equities are the same. Some companies fall under the purview of growth stocks, while others meet criteria necessary to be deemed value stocks. For mid-cap equities that are considered undervalued in the market, investors have an additional opportunity to achieve greater than average return on an investment. Mutual funds that invest primarily in mid-cap value stocks offer diversity across a range of sectors and geographical regions, and provide investors a method to spread risk in an efficient way.

Fidelity Mid Cap Value Fund

The Fidelity Mid Cap Value Fund was established in February 2007 and seeks to provide investors with capital appreciation over the long term. The fund's managers invest no less than 80% of the fund's $3.91 billion assets in securities of companies with medium-sized market capitalizations, similar to those found within the Russell Midcap Index or the S&P MidCap 400 Index. Fund managers have the ability to invest in equities of companies in small- and large-cap categories as well, and can diversify among domestic and foreign issuers. As of December 2015, the fund has generated a five-year annualized return of 13.65%.

The fund's managers diversify holdings across a broad range of industries, including financial services at 23.84%, technology at 12.50%, consumer cyclical at 10.96% and utilities at 9.68%. The majority of fund assets are held in domestic issuers, but the fund does provide exposure to Greater Europe at 6.35% with a focus on developed markets. Companies that fall within the mid-cap category make up 49.35% of the portfolio, followed by large-cap holdings at 34.91% and small-cap companies at 10.99%. Top holdings within the portfolio include Discover Financial Services at 2.32%, Teva Pharmaceutical Industries at 2.12% and Allstate at 2.01%.

The expense ratio for the Fidelity Mid Cap Value Fund is 1.15%, and investors are charged an upfront sales load of 5.75%. No deferred sales charge is assessed when investors redeem shares. A minimum initial investment of $2,500 is required.

American Century Mid Cap Value Fund

The American Century Mid Cap Value Fund was established in 2005 and seeks to provide long-term growth of capital to investors with income as a secondary objective. The fund's managers invest no less than 80% of the fund's $6.63 billion assets in mid-cap companies, similar to those found within the Russell 3000 Index. Investment selection for holdings is based on a number of value characteristics, including a stock being temporarily out of favor with investors and its potential to increase in price over time. As of December 2015, the fund has generated a 10-year annualized return of 8.75%.

The majority of the fund's holdings are domestic securities, but fund managers diversify in terms of sector exposure. Financial services companies make up 21.86% of the portfolio, followed by industrial companies at 12.96%, energy companies at 11.8%, utilities companies at 10.61% and consumer defensive companies at 9.6%. Top holdings include Republic Services at 2.97%, Northern Trust at 2.74%, Sysco at 2.73% and Imperial Oil at 2.05%.

The expense ratio for the American Century Mid Cap Value Fund is 1.26%, and investors are assessed an upfront sales load of 5.75% when they purchase shares. No deferred sales load is charged upon redemption, and a minimum initial investment of $2,500 is required.

T. Rowe Price Mid-Cap Value Fund

The T. Rowe Price Mid-Cap Value Fund was established in 1996 and seeks to provide investors with capital appreciation for the long term. The fund's managers invest at least 80% of the fund's $11.37 billion assets in companies that fall within the mid-cap range defined by the S&P MidCap 400 Index or the Russell Midcap Value Index. The fund's managers focus on mid-cap equities with value characteristics. As of December 2015, it has generated a 10-year annualized return of 8.1%.

The mutual fund's portfolio substantially consists of domestic equity positions, although fund managers diversify based on sector categorization. Financial services has the heaviest weighting within the fund, making up 26.72% of the investment mix. Consumer cyclical stocks make up 11.26% of the portfolio, followed by consumer defensive stocks at 11.21%, basic materials stocks at 10.94% and industrial stocks at 9.81%. While the fund is focused on mid-cap equities, 21.72% of the portfolio is made up of large-cap companies, and 17.48% is in small-cap companies. Top holdings include FirstEnergy at 2.75%, Sysco at 2.64%, Hologic at 2.49% and Northern Trust at 2.43%.

The T. Rowe Price Mid-Cap Value Fund has an expense ratio of 0.8%, and it is considered a no-load fund for both purchase and redemption of shares. Investors are required to provide a minimum initial investment of $2,500.

Sterling Capital Mid Value Fund

The Sterling Capital Mid Value Fund was established in 1996 and seeks to provide long-term growth of capital by investing in undervalued equities. The fund's managers invest a minimum of 80% of the fund's $668.33 million assets in securities of companies that fall within the mid-cap range at the time of purchase. The fund's managers can invest in domestic or foreign issuers, but the fund focuses on common stocks of U.S. companies. As of December 2015, the mutual fund has generated a 10-year annualized return of 7.48%.

While the fund does not provide exposure to foreign markets, its managers diversify assets in terms of market sector. Financial services comprise 33.03% of the portfolio, followed by consumer cyclical stocks at 23.33%, industrials at 14.66%, technology at 11.68% and health care at 9.43%. Mid-cap companies make up 53.78% of the total investment mix, followed by 19.97% in large-cap equities and 18.95% in small-cap. Top holdings within the mutual fund include Omnicom Group at 4.53%, Leucadia National at 4.38%, Markel at 4.07% and E*Trade at 3.98%.

The Sterling Capital Mid Value Fund has a net expense ratio of 1.18%, and investors are charged an upfront sales load of 5.75%. No deferred sales charge is imposed, but a minimum initial investment of $1,000 is required.

Lord Abbett Mid Cap Stock Fund

The Lord Abbett Mid Cap Stock Fund was established in 1983 and seeks to provide investors with capital appreciation by investing in equity securities. The fund's managers invest at least 80% of the fund's $2.26 billion assets in mid-cap company securities in domestic and foreign markets. Fund managers hone in on equities with value characteristics regardless of sector or region. As of December 2015, the mutual fund has generated a 10-year annualized return of 5.18%.

While the fund's managers can invest in developed and emerging markets outside the United States, no foreign exposure exists within the current investment mix. However, diversification is present across sector categories, including financial services stocks at 22.62%, real estate equities at 12.93%, technology companies at 11.43% and utilities companies at 10.79%. Mid-cap companies make up the majority of the fund's portfolio at 63.59%, followed by large-cap companies at 22.78% and small-cap companies at 13.63%. Top holdings include Hartford Financial Services Group at 2.58%, XL Group at 2.41%, M&T Bank at 2.24% and Edison International at 2.17%.

The Lord Abbett Mid Cap Stock Fund has an expense ratio of 1.11%, and an upfront sales charge of 5.75% is assessed when shares are purchased. There is no deferred sales charge, but a minimum initial investment of $1,000 is required.