One of the primary reasons so many advisors and investors gravitate to ETFs over mutual funds is the low fees available on ETFs. An often overlooked reason why so many retail investors embrace ETFs over mutual funds is minimum investments.As in many mutual funds require minimum investments while no ETFs do. Some mutual funds have tolerable minimum investments of $500 or $1,000. Others start at $2,500 or $3,000 while some other mutual funds require minimum investments that makes these funds off-limits to a large portion of investors.Another irksome point about mutual funds' minimum investments that the higher the required investment, the lower a fund's fees are likely to be. With ETFs, the expense ratio is the expense ratio, regardless of how much investors put into the fund.InvestorPlace - Stock Market News, Stock Advice & Trading Tips"The main thing to understand is that the lower the investment minimum, the higher the expense ratio usually is," according to Morningstar. "The reasoning is that it's more difficult to maintain many accounts with low balances than fewer accounts with lots of assets. So although the strategy and investment portfolio (and investment manager, if applicable) are the same across all share classes, the expense ratios will differ." * 7 Top Stocks to Buy From Goldman Sachs' Secret Portfolio Here are some examples of mutual funds with minimum investments that are likely to catch investors' eyes -- but not in a good way. Vanguard S&P Mid-Cap 400 Index Fund Institutional Shares (VSPMX)Minimum investment: $5,000,000.No need to do a double-take. The Vanguard S&P Mid-Cap 400 Index Fund Institutional Shares (MUTF:VSPMX) really does have a minimum investment of $5,000,000, according to Vanguard data.In fairness to this Vanguard mutual fund, VSPMX, at its name implies, is the institutional share class of a mutual fund with several share classes. But all of these have required investments that are significantly lower than $5,000,000.And for investors that want to dodge minimum investments altogether, the this mutual fund is available in ETF form via Vanguard S&P MidCap 400 ETF (NYSEARCA:IVOO). That ETF charges just 0.15% per year. Vanguard Health Care Fund Investor Shares (VGHCX)Minimum investment: $3,000There was a time when the Vanguard Health Care Fund Investor Shares (MUTF:VGHCX) had a minimum investment that was far higher than the $3,000 investors see today. This is an actively managed healthcare mutual fund with a lengthy track record."For more than 25 years, this actively managed fund has offered investors low-cost exposure to domestic and foreign companies involved in various aspects of the health care industry, such as pharmaceutical firms, medical supply companies, and research firms," according to Vanguard. * 5 Warren Buffett Stocks You Can't Go Wrong With While it is not an ETF replica of VGHCX, the Vanguard Health Care ETF (NYSEARCA:VHT) is a suitable alternative for investors looking for lower-fee, no minimum investment product. VHT charges just 0.10% per year, making it one of the least expensive healthcare funds -- ETF or mutual fund -- on the market. Calamos Convertible I (CICVX)Minimum Investment: $1,000,000This share class of the Calamos Convertible I (MUTF:CICVX) really does require a minimum investment of $1,000,000. Fortunately, the issuer has a pair of other share classes for this mutual fund that have much more reasonable minimum investments of $500.Convertible bonds are popular with some fixed income investors because the bonds can be converted into common stock of the issuing company, giving convertibles higher correlations to stocks than other fixed income asset classes. Plus, convertibles often perform well when interest rates rise.Over half the bonds in this mutual fund are issued by technology and healthcare companies. The fund has a 30-day SEC yield of 1%. AQR Large Cap Defensive Style Fund (AUEIX)Minimum investment: $100,000 or $5,000,000The AQR Large Cap Defensive Style Fund Class I (MUTF:AUEIX) has a minimum investment of $100,000, but that is only for institutional investors. Individual investors that want to get involved with mutual fund face a minimum investment of $5,000,000, according to issuer data.Hey, at least this mutual fund does not have loads or redemption fees. In many ways, AUEIX is a standard large-cap mutual fund, looking to capture upside in bull markets while potentially experiencing less downside when markets decline. * 7 Growth Stocks Racing to All-Time Highs At the end of last year, AUEIX allocated almost a third of its combined weight to the defensive healthcare and consumer staples sectors. Technology and financial services stocks combined for 29.40% of the mutual fund's weight. Vanguard Consumer Staples Index Fund Admiral Shares (VCSAX)Minimum investment: $100,000.This is another case of a particular share class of a Vanguard mutual fund carrying a high required investment while also having several more affordable share classes. The Vanguard Consumer Staples Index Fund Admiral Shares (MUTF:VCSAX) is an index fund, not a mutual fund, tracking a sector that is popular with conservative, income-oriented investors.This mutual fund's roster "includes stocks of companies that provide direct-to-consumer products that, based on consumer spending habits, are considered essential to daily life," according to Vanguard.Investors can dodge the required minimum investment with the Vanguard Consumer Staples ETF (NYSEARCA:VDC), which is also one of the least expensive staples ETFs on the market.Todd Shriber does not own any of the aforementioned securities. More From InvestorPlace * 2 Toxic Pot Stocks You Should Avoid * 7 Growth Stocks Racing to All-Time Highs * 5 Warren Buffett Stocks You Can't Go Wrong With * Game On for These 3 Gaming Stocks Compare Brokers The post 5 Mutual Funds With Huge Minimum Investments appeared first on InvestorPlace.