No one invests in the stock market to lose money. Yet it often seems like the people who lose their shirts outnumber those who strike it rich. While there's no guaranteed way to prevent losing money in the market, recognizing these three common blunders can save your portfolio from a lot of pain.

Fear and greed are said to be the two emotions that drive most investing decisions, and following either of them can lead you to lose all of your money. While it's not easy to be devoid of all emotion when putting your money in the stock market, reining them in can help keep you from losing your shirt.

Digital representation of a crashing stock market

Image source: Getty Images.

With that in mind, here are three common mistakes many investors make, both those new to investing as well as some old salts who have been through a few market cycles. Although there's no guarantee you won't suffer losses on a stock, recognizing these forced emotional errors can help you minimize the pain your portfolio experiences.

1. Day-trading (or even frequent trading)

Jumping in and out of stocks trying to time entry and exit points is a sure-fire way to lose your money, which is why you'll find there are few if any day-traders who have a long-term record of success.

There is a certain allure to the "easy money" that comes from buying and selling stocks as they twitch higher and lower, but in reality, it's a (small-f) fool's errand. It's hard enough to figure out what a stock will do five or 10 years down the road, let alone how it's going to react tomorrow or 15 minutes from now -- or three seconds from now! Yet day-traders are flitting from one position to the next, racking up transactional costs and hoping each trade wins.

It's just not easy to successfully make winning bets like that time after time. Yet beyond day-trading, even moving in and out of positions over days or weeks isn't any easier. It gives the impression that you know the precise time to buy in or sell out, but actually, you almost always miss the top or bottom, and a stock runs away from you.

There's a reason the most successful investors -- Buffett, Lynch, Klarman, and more -- are long-term buy-and-hold types. It doesn't mean they never sell, it's just that the times they do are few and far between. You'd be better off emulating their strategies than trying to time a stock.

Pennies piled on a stock chart

Image source: Getty Images.

2. Playing penny stocks

Along with buy-and-hold, the investing legends don't invest in penny stocks, and the reason is simple: It's because they are losing propositions. While here and there you may be able to find one company that makes good on its promise, the vast majority of times, you're going to wind up on the losing side of the coin toss.

There are a few reasons for this. Penny stocks are so tiny, they tend to be very thinly traded, which makes them ripe for manipulation. They also tend to be built on "ideas," but have few ways of achieving them. They tout they're turning themselves into the next Microsoft or Wal-Mart, but often, their promoters are just seizing on the latest hot idea -- lithium batteries, solar power, rare earth minerals, gold mining, etc. -- and they're trying to churn up interest in the stock to get the price to jump, so they can bail out and reap a windfall while you're left holding essentially worthless paper.

Sure, controlling thousands of shares for a relatively paltry investment is exciting, and if they only run up a few nickels in value, you've got a terrific score. Unfortunately, few penny stocks do that without being some pump-and-dump scheme. Ultimately, this isn't investing, but gambling, and the odds of winning are worse than going to a casino.

Woman with debt

Image source: Getty Images.

3. Using margin

Leveraging an investment by taking on debt in a bid to amplify a stock's return can be a powerful tool in the right hands, but like credit card debt that can quickly mire a person in a lifetime of servitude to paying it off, using margin is generally a losing bet.

It's not that margin is a complicated or sophisticated tool. It's actually very easy. Too easy, in fact. You're taking a loan out on the value of your portfolio and using the proceeds to buy stock. Yet because it is so easy to misuse, it should only be employed sparingly, if at all.

The problem is, in a rising market like the one we're currently enjoying, it's easy to think you're an investing genius, and all your picks will do well. Tapping into margin to enhance your returns is only good until the next nasty downturn, and then buying stocks on margin can become quite painful.

All it takes is just one stock you've margined to the max to drop in value -- and it doesn't even have to fall all that far -- and you can be faced with the dreaded margin call: Either put more money into your account immediately, or face having your portfolio sold off to make up the difference.

Debt can be good. A mortgage, for example, can be an appropriate use of debt. But taking out a second mortgage and using the funds to go gamble in Las Vegas would be a misuse, and that is essentially what buying stocks on margin is. Picking good stocks with good businesses that are trading at reasonable valuations, and then holding them through thick and thin, will usually provide you with superior returns so you don't need to finance your portfolio with dangerous debt.

Teresa Kersten is an employee of LinkedIn and is a member of The Motley Fool's board of directors. LinkedIn is owned by Microsoft. Rich Duprey has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.