(MONEY Magazine) – A rock-solid balance sheet is like a blue blazer or a little black dress. It's always fashionable no matter the season. So in an anxious market like today's, investing in a company with little or no debt and plenty of cash should be the default, much like those style stalwarts are when you don't know what to wear.

Among the companies that stand out as the embodiment of financial stability is Pfizer (PFE), whose annual sales of $51 billion make it the world's largest drugmaker. Pfizer not only has $17.5 billion in cash on hand, but its total liabilities—both short- and long-term debt—account for less than 10% of its $245 billion market cap. "Financially, it's a phenomenal company," says John C. Thompson, who is accumulating Pfizer shares for his Thompson Plumb Growth, a MONEY 100 fund.

What's more, Pfizer has got 14 of the world's 25 best-selling pharmaceuticals, including Lipitor for high cholesterol, the most prescribed medicine of any kind in the world. Nine of the company's blockbuster drugs each boast sales of more than $1 billion a year. And in terms of market value, Pfizer is twice the size of its closest competitor, Britain's GlaxoSmithKline.

At the moment, however, investors aren't giving Pfizer much credit for its phenomenal finances or its industry leadership. Instead, they fret that too many of Pfizer's customers will figure out how to buy their drugs in Canada, where price controls put a serious squeeze on all U.S. drug companies' lush profit margins. Candidate Kerry's promise to lower voters' health-care costs by squeezing drug company profits hasn't helped either. Then there are Pfizer's own particular problems. Four of its top-selling drugs, including the blockbuster antidepressant Zoloft, will go off patent by 2006, exposing them to competition from cheaper generics. Moreover, there haven't been enough promising new products in the pipeline to take their place; Pfizer's last big drug launch was Viagra in 1998.

Investors are so sure that Pfizer's pill jar is half empty that recently they would pay no more than $15 for every $1 of Pfizer's $2.13 expected 2004 profit. That's almost a 10-year low.

To invest in Pfizer now, in other words, is to bet that the company can ride out these challenges. And that's where the company's granitelike balance sheet comes in. A less sound company would be slashing budgets, not raising them as Pfizer has over the past three years. With $17.5 billion in cash and a modest debt load, Pfizer can easily maintain its $7 billion research-and-development budget—the industry's largest and the source of the discoveries that are a pharmaceutical maker's lifeblood. The New York company can also afford to expand its 12,000-strong sales force, considered the best in the industry.

Thanks to those same sound finances, Pfizer can also continue to do the things that mollify shareholders: buy back stock ($7.5 billion in the past year) and steadily boost its dividend payment (now at 68¢ a share). "It could keep up those buybacks and payouts indefinitely and still grow," Thompson says. And that kind of performance never goes out of style.