7 of the Most Common Investing Mistakes

Successful investors avoid these costly mistakes.

Investing is one of the best ways to build long-term wealth. As you invest over time, you're likely to see solid returns and beat inflation. However, not every investing idea is a good one and if you aren't paying attention to what you're doing, you could make costly mistakes. Here are some of the most common investing mistakes to avoid. And if you've already made some of these mistakes, don't think it's too late. Once you recognize the mistake, you can take steps to improve -- and be richer in the future.

Waiting too long to start.

Don't put off investing. There are a number of excuses that people use to explain why they haven't started investing yet, ranging from "I don't have enough money" to "I don't know what to invest in." The good news is that just about anyone can start investing with a small amount of money. Applications and companies that facilitate investing with small amounts are readily available. And, if you're not sure what to invest in, using an indexing strategy or starting with a robo advisor can be an easy way to move forward while you learn the ropes.

Not investing enough when you have the resources.

Once you get in the habit of investing, it's important to also get in the habit of investing more. Let's be honest. If you're investing $200 a month, that's probably not enough to build the retirement portfolio of your dreams. As your resources increase, so, too, should the amount you invest. Use an investment or retirement calculator to help you better estimate how much you should be setting aside for a successful future.

Paying too much in fees.

Fees might not truly make or break your portfolio, but they can erode your real returns. The more you pay in fees, the less you end up with over time. Look for brokerages that charge lower fees. You can also find low-cost funds, like index funds and exchange-traded funds, or ETFs, that can have lower expense ratios. In some cases, a good manager can provide you with large enough returns to make up for the fees, but for many investors, paying attention to fees -- and paying less -- can help boost returns in the long run.

Buying (and selling) based on emotion.

Another common investing mistake is buying and selling based on emotion. You might be caught up in the excitement of a new investment, ready to buy because of the hype. This can lead you to invest in assets without completing due diligence or research. In the end, you could end up losing out. The flip side of this issue is selling based on emotion. Panicking when the market is down and selling because you're scared of what's happening only serves to lock in losses. Selling an investment requires careful thought -- just like buying. Before you buy or sell, make decisions based on logic and planning, not emotion.

Frequent trading.

There are day traders who make a lot of money. But for most investors, frequent trading can be a costly mistake. When you trade too much, you run the risk of fees that cut into your real returns. Next, frequent trading involves being able to understand when it's the right time to act, which is difficult to pinpoint and can lead to large losses. Finally, frequent trading -- especially day trading -- can be stressful. You have to be prepared to lose a big chunk of money one day and comfortable with the thought that you'll have to make it up the next. That takes a high risk tolerance and a strong stomach.

Buying when everyone else is.

By the time an investment is so popular that everyone is buying it, that's the point at which it's likely already peaked. In general, people get super excited and buy when an asset has already had its run up in price. By definition, if everyone is buying, you're already late to the party. You might be able to eke out some gains, but that's likely to happen only after the inevitable correction.

Believing you have to beat the market to be successful.

It's nice to be able to brag about "beating the market." Outperforming the market makes you feel smart. However, the reality is success isn't about whether you beat the market. Instead, it's about whether you're investing in a way that helps you reach your long-term goals. You don't have to beat the market to be an investing success. Instead, it's all about making sure your portfolio is growing and that you'll have what you need in the future. In many cases, just keeping pace with the market with the help of indexing is all you need to be successful in the long term.

The most common investing mistakes.

-- Waiting too long to start.

-- Not investing enough when you have the resources.

-- Paying too much in fees.

-- Buying (and selling) based on emotion.

-- Frequent trading.

-- Buying when everyone else is.

-- Believing you have to beat the market to be successful.

Miranda Marquit has more than a decade of experience covering financial markets, investing, business, and personal finance topics. She has made contributions to a wide variety of media outlets, including Forbes, NPR, FOX Business, Entrepreneur, Yahoo! Finance, USA Today, Investopedia, The Balance, and MSN Money, in addition to U.S. News & World Report. Miranda has a master's degree in journalism from Syracuse University and is working on her MBA. She also writes about personal finance and investing for her blog "Planting Money Seeds" and contributes to the successful Money Tree Investing Podcast. When not writing about money, Miranda enjoys spending time with her son, traveling, reading, and the outdoors.