It's undoubtedly been difficult for many individual investors to avoid the temptation to snap up shares of well-known companies now trading in the penny stock range. If you're one of them, I implore you: Don't give in to that temptation without doing your homework. Most of those beaten-down stocks are in the dumps for good reason.

The macroeconomic climate right now is brutal. Massive deleveraging is nothing to mess around with. Many companies will be blown right out of the water. Many consumers had too much debt. So did many companies. It's a terrible brew of nastiness.

And now that consumers are dealing with plunging asset values, untenable debt, and increasing job losses, many companies' sales are understandably pinched, making it more difficult to service their own debt or borrow more to fund their operations. All of which makes for one seriously ugly domino effect.

Going, going, gone?
Last year, many people made wild bets on financial stocks like Fannie Mae, Freddie Mac, and Merrill Lynch. I'd guess that many of these folks unwisely ignored those companies' balance sheets, which are more important than ever in these troubled times.

The folly of shoddy due diligence has become evident in the increasing numbers of companies disclosing "going concern" warnings from their auditors. You can find those warnings in a company's quarterly (10-Q) or annual (10-K or 20-F) filings with the Securities and Exchange Commission.  Usually, there will be a paragraph with language about factors that "raise substantial doubt as to our ability to continue as a going concern." Need a well-publicized recent example of a company where increasing financial difficulties made people wonder about its ability to continue as a "going concern"? Look no further than CIT Group (NYSE:CIT).

When companies find it increasingly difficult to make ends meet, have negative cash flow, or can't find anybody to lend them money, auditors often eventually question their abilities to stay upright and in one piece. As you can imagine, such questions are popping up a lot more often these days.

Image Entertainment (NASDAQ:DISK), Hoku Scientific (NASDAQ:HOKU), Russia's Mechel (NYSE:MTL), Security Bank (NASDAQ:SBKC), and inTEST (NASDAQ:INTT) have all disclosed such auditor warnings recently. Even though some of these companies are taking action to fix their problems -- Mechel, for one, has received a respite through short-term refinancing -- it's still a dire sign that investors should take very seriously.

Accountants are usually reluctant to issue such warnings. According to a recent survey, only about half of companies that filed for bankruptcy in 2001 had actually received "going concern" warnings. So you can bet that when a company does receive one, accountants believe it faces some serious issues.

The proliferation of these warnings should lead investors to think twice about the beleaguered, supposedly "cheap" stocks they're choosing for their portfolios. There could be more spectacular flameouts on the way. The U.S economy -- and consumer -- is in bad shape, and many struggling, overindebted companies simply won't be able to survive.

Go for the gold, not for the goners
But plenty of stocks out there do represent strong companies with good management and little or no debt -- the kind of companies positioned to survive macroeconomic hardship while beleaguered rivals get taken out.

The team at Motley Fool Stock Advisor, which is beating the S&P by more than 40 percentage points, seeks out only the highest-quality companies. For example, newsletter recommendation Netflix (NASDAQ:NFLX) has a great brand, a loyal customer base, a boatload of cash on its balance sheet, and negligible debt.

Of course, as is always the case with investing, Netflix is not risk- free. Consumers could curtail their budgets and ditch Netflix subscriptions if economic malaise continues for too long. However, Netflix's history of innovative excellence and plush cash position vastly increase its odds of long-term survival. It's a good example of the kind of quality stocks investors should search for.

It takes a certain amount of bravery to invest these days, but however tempting the smorgasbord of beaten-down stocks may appear, let's all try to avoid too much speculative bravado. Go for the gold, not the goners. If you're looking for more stock ideas, you can click here to read more about the Stock Advisor team's favorite picks, free for the next 30 days.

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This article was originally published on May 12, 2009. It has been updated.

Alyce Lomax does not own shares of any of the companies mentioned. Netflix is a Stock Advisor selection. The Fool has a disclosure policy.