On days like today, when the markets were in a freefall, I like to turn to an oft-quoted but rarely followed quote from one of the world's greatest investors: "Be fearful when others are greedy and greedy when others are fearful."

Across the board, investors were running scared today. The Dow Jones Industrial Average (Index: ^DJI) shed more than 312 points, the S&P 500 (NYSE: ^GSPC) lost more than 33 points, and the Nasdaq (SNPINDEX: ^IXIC) was down 74 points. All three indexes lost more than 2.36% during today's trading session. Now, I can understand why some investors are fearful. They lost money today, and they may believe that they will lose more in the coming days. Of course, it's very possible that the markets may indeed continue to fall over the next few days, weeks, or even months.

So why could this be a good thing? Because if we follow what Warren Buffett has said about being greedy at times like this, we can follow in his footsteps and buy great companies at drastically reduced prices -- and make lots of money doing it.

Let's first look at the five biggest losers of the Dow today: Bank of America (NYSE: BAC) lost 7.14%, JPMorgan Chase (NYSE: JPM) was down 5.6%, Hewlett-Packard (NYSE: HPQ) fell by 4.93%, UnitedHealth Group (NYSE: UNH) shed 3.78%, and Intel (Nasdaq: INTC) cut off 3.77%. One could argue that any or all of these companies have a number of issues and the moves lower are related to overall poor businesses, and therefore justified. But by that same token, all of these stocks are cheaper now than they were yesterday, and if you do believe in the business, now could be a great time to buy.

A case for the banks
Bank of America is up 66% year to date, while JPMorgan has risen 21% during that same time frame. My Fool colleague Matt Koppenheffer noted earlier today that the banks and the markets in general have performed fairly well during the Obama administration and that if today's sell-off is due to the outcome of the election, then today's drop is way overdone. Although many investors believe the current administration will crack down more on the financial industry, we have to remember it has been those same individuals who believe in keeping interest rates low, making it easy for the banks to shore up their balance sheets.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.