Going from a good investor to a great investor means grabbing great opportunities faster than a speeding bullet. Without one key resource in your investing toolbox, however, you could miss out on the chance to become the world's next great super-investor.

I'm not talking about a particular stock or group of stocks. I'm not here to recommend a specific mutual fund or exchange-traded fund (ETF), nor will you see me talk up commodities or encourage you to trade in the foreign exchange markets.

But what is essential is the tool that will let you have access to all of those investments and more when you need them. That tool is a discount brokerage account, and it's easier than ever to find a broker that's the perfect fit for you.

How to live without a broker
It's true that you don't absolutely have to have a brokerage account to invest. Even if you never work with a broker, there are thousands of mutual funds you can buy directly from fund companies. Those funds can open the door to every corner of the investing world, and you can easily put together an investing strategy that has a strong chance of helping you achieve all of your financial goals. And they're very well-diversified, usually holding anywhere from 20 to hundreds or even thousands of different investments.

But if you want to invest in individual stocks, mutual funds are certainly not the answer. However, you're still not out of luck even if you don't have a broker. Through direct stock purchase plans, you can buy shares of dozens of stocks directly from the companies themselves. Many companies let you buy shares without a huge initial investment. For instance, one transfer agent offers direct investment plans in the following stocks to investors, some of which offer fairly reasonable minimum purchases:

Stock

Minimum Initial Purchase

ExxonMobil (NYSE:XOM)

$250

Ameriprise Financial (NYSE:AMP)

$1,000

Best Buy (NYSE:BBY)

$500

FedEx (NYSE:FDX)

$1,000

Intel (NASDAQ:INTC)

$250

Oshkosh

$100

Nike (NYSE:NKE)

$500

McDonald's (NYSE:MCD)

$500 ($100 for custodial account)

Source: Computershare.

As you can see, you could build up a nice-sized portfolio of individual stocks without a lot of money -- and even if you never open a brokerage account.

What you're missing
On the other hand, sticking with mutual funds and direct stock purchase plans puts some limits on your investing. Here are some of the things that a discount broker can offer you that funds and direct stock plans can't:

  • Selection. Although many companies offer direct purchase plans, not all do. If you want to go beyond major, well-known companies, then only a broker offers easy access to every stock you might ever want to invest in.
  • Spontaneity. With direct purchase plans, there's a delay between when you want to make an investment and when you actually purchase your shares. Similarly, mutual funds only execute trades once per day. With a broker, however, you can buy shares when and how you want.
  • More strategies. Funds are fine for vanilla investments like stocks and bonds. But if you want to take your investing to the next level by considering other strategies, including options, futures, and ETFs, then you'll need a brokerage account to take full advantage.
  • Research. With direct stock purchase plans, you're pretty much on your own when it comes to deciding which stocks to buy. Although there are useful free resources on the Internet, most discount brokers now offer special research tools that can help you monitor your positions, follow breaking news that affects your investments, and execute trades in the most efficient way possible.

Moreover, given how inexpensive discount brokers have become, there's really almost no reason not to open a brokerage account.

Give it a try
If you've avoided investing with a broker thus far, either because you're fearful of the stock market or you wish not to get badgered by aggressive salespeople, take another look at discount brokers. The right broker could give you the tools you need to reach your full potential as a top investor.

If you're shopping for a broker, let us help you make the right choice. Our discount broker collection will show you what various brokers have to offer and give you a list of guidelines for choosing the best one for you.

Fool contributor Dan Caplinger thinks Robert Downey Jr. should give up his Iron Man role and become Super-Investor. Dan doesn't own shares of the companies mentioned in this article. Best Buy and FedEx are Motley Fool Stock Advisor picks. Best Buy and Intel are Motley Fool Inside Value selections. The Fool owns shares of Best Buy. Try any of our Foolish newsletters today, free for 30 days. The Fool's disclosure policy has the superpowers you need to succeed.