Investing can sometimes be an expensive endeavor, especially if you're investing in individual stocks. Some stocks can cost hundreds or even thousands of dollars per share, and it's wise to invest in at least 10 to 15 stocks to diversify your portfolio and limit your risk.

Not everyone can afford to invest that much, especially right now when money is tight for millions of American households. Fortunately, there are several low-cost options for those who want to invest in the stock market on a budget. However, not all investment options are created equal, so it's important to make sure you're choosing the right approach for you.

Man holding hundred dollar bills

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Penny stocks

Penny stocks are securities that trade for less than $5 per share, according to the Securities and Exchange Commission, and they're typically issued by very small companies.

Many investors are drawn to penny stocks because they're so inexpensive. However, these stocks can also be incredibly risky, so they're not for the faint of heart. Because they're primarily issued by small companies, they're generally much more volatile than stocks from larger organizations. You could see explosive gains, but you could also experience sizable losses. And because these small companies often don't have a proven track record like large corporations, it can be tougher to determine which stocks will perform well over time.

For those reasons, it's typically best to avoid penny stocks unless you have a strong tolerance for risk. If you're on a tight budget and aren't prepared for the potential losses, penny stocks may not be the right option for you.

Fractional shares

Fractional shares are simply partial shares of a stock, and they can be a smart choice if you want to invest in a particular company but can't afford to buy a full share of that company's stock. Especially if you want to invest in a company whose stock sells for hundreds or thousands of dollars per share, buying fractional shares can be a more affordable alternative.

Fractional shares also make it easier to diversify your investments on a budget. If you have, say, $1,000 to invest, you may only be able to buy a few full shares of stock, depending on which companies you invest in. But with fractional shares, you can spread your cash across dozens or even hundreds of different companies, thus limiting your risk. You only need a few dollars to invest in fractional shares, so it's easier to get your feet wet at an affordable price.

Index funds

Index funds are large collections of stocks that follow a particular market index, such as the Dow Jones Industrial Average or the S&P 500.

As with fractional shares, you can invest in hundreds of different companies at a fraction of the cost of buying full shares of individual stocks. The difference between fractional shares and index funds, however, is that with index funds, you don't have to choose which companies you invest in. Because index funds simply track certain indexes, you're automatically investing in the companies included in that index. So, for instance, if you invest in an index fund that tracks the S&P 500, you're investing in all the companies that are included in the S&P 500.

For many people, index funds are a good choice because they're low-cost and lower-risk than many other types of investments. Index funds follow the market, so they're more likely to bounce back if the stock market takes a turn for the worse. They're also more hands-off than investing in individual stocks, because you don't need to research each company you're investing in to ensure it's a solid long-term investment.

Which option is right for you?

All three options offer the chance to invest in the stock market at a more affordable price than investing in full shares of individual stocks, but which option you choose will depend on your investing style as well as your tolerance for risk. If you want to limit your risk as much as possible, index funds may be the way to go. But if you want to play around with individual stocks, investing in fractional shares could be a smart option.

Keep in mind, too, that you're not limited to just one of these options. You may build a solid foundation with index funds first, for example, then use any leftover cash for other investments.

Investing in the stock market is more affordable than you may think, and it's possible to build a solid portfolio even if you don't have much spare cash. By taking advantage of one or more of these low-cost investing options, you can save more for the future without breaking the bank.