When capital appreciation over the long-term takes precedence over dividend payouts, growth funds become a natural choice for investors. However, investors looking for the highest capital gains should look no further than investing in aggressive growth mutual funds.For the risk takers whose objective is to seek the highest capital gains, aggressive growth mutual funds are the best option to invest in.

Aggressive growth funds invest in companies that show high growth prospects, but that comes with the risk of share price fluctuations. This category of funds also invests heavily in undervalued stocks, initial public offerings (IPOs), and relatively volatile securities in order to profit from them in a friendly economic climate. Securities are selected on the basis of their issuing company’s potential for growth and profitability.

This category of instruments has a strong positive correlation with market movements and provides good returns during a market upswing. Such performance is achieved by investing in securities issued by companies with strong growth potential and in IPOs which are often resold quickly at a handsome profit. Many aggressive growth mutual funds may also invest in options to achieve their goal of high returns.

3 Aggressive Growth Funds to Buy

Below we present three top-ranked mutual funds with aggressive growth investment objectives. Each has earned a Zacks Mutual Fund Rank #1 (Strong Buy) or a Zacks Mutual Fund Rank #2 (Buy) as we expect these mutual funds to outperform their peers in the future.

Remember, the goal of the Zacks Mutual Fund Rank is to guide investors to identify potential winners and losers. Unlike most of the fund-rating systems, the Zacks Mutual Fund Rank is not just focused on past performance, but the likely future success of the fund.

The funds have relatively low expense ratio and carry no sales load. They also have decent year-to-date, one-year, and three-year, and five-year returns.

PRIMECAP Odyssey Aggressive Growth (POAGX - MF report) prioritizes investing in U.S. companies with rapid earnings growth potential. Though the fund invests across market sectors and market capitalizations, it has historically invested most of its assets in mid- to small-cap firms.

POAGX currently carries a Zacks Mutual Fund Rank #2 (Buy).It has returned -3.21% year to date, but its three- and five-year returns stand at healthy 16.38% and 15.26%, respectively. The fund carries an expense ratio of 0.62% and a net asset value of $6.50 billion.

Vantagepoint Aggressive Opportunities Investor (VPAOX - MF report) seeks capital growth over the long term. It invests using an actively-managed strategy in stocks of small- to mid-cap domestic and foreign firms, which are believed to have high capital growth prospects. The fund also invests in stocks listed in a custom version of the Russell Midcap Growth Index.

VPAOX currently carries a Zacks Mutual Fund Rank #2 (Buy). It has returned 7.97% and 6.82% over the three- and five-year periods. The fund carries an expense ratio of 0.83% as compared to category average of 1.31%. VPAOX has a net asset value of $31.61 million.

Vanguard Growth Index Fund (VIGRX - MF report) seeks long-term capital growth. The fund holds all of the stocks in the unmanaged Standard and Poor's Growth Index in approximately the same proportions as those stocks represent in the index. It attempts to match the performance of the index, and remains fully invested in stocks at all times. 

VIGRX currently carries a Zacks Mutual Fund Rank #1 (Strong Buy). It has returned only 0.30% year-to-date, but has impressive three- and five-year returns of 12.41% and 11.94%, respectively. The fund carries an expense ratio of 0.22% and a net asset value of $2.81 billion.