Not paying attention to U.S. stocks recently? Perhaps the thrilling spectacle of the Olympics kept you away from your portfolio. Or the no less engrossing public split of Tom Cruise and Katie Holmes made you forget about your 401k. Maybe it was the languid summer, William Shatner's return as Priceline's "negotiator," or the struggles of the Red Sox and Arsenal.

Whatever the reason, here is a quick way to get reacquainted with recent stock-market history: Slide open your iPhone, check your Facebook (FB) page and you are done.

That's right. The last few months in the world of equities can be summed up in the opposing fortunes of Apple (AAPL) Inc. and Facebook Inc.. One is sitting atop the corporate world, having just been crowned the largest-ever U.S. company by market capitalization. (There is an asterisk, but more on that later.) The other is struggling with a share price that has nearly halved since a messy initial public offering in May.

The gap between the values placed by investors on Apple and Facebook around $621 billion and $42 billion, respectively is large enough to fit the economy of South Africa. But the distance between the yin and the yang of the U.S. stock market is more telling than that and offers three insights into investors' current thinking.

 

The Stocks World According to Apple and Facebook

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Not paying attention to U.S. stocks recently? Whatever the reason, here is a quick way to get reacquainted with recent stock-market history: Slide open your iPhone, check your Facebook page and you are done. Photo: Getty Images.

First, pervasive uncertainty and ultralow interest rates are prompting the market to look at the long term. By ascribing such a large value to Apple, investors are betting on the company being alive and well for a long time.

This isn't just a gut reaction but a belief in Apple's continued ability to generate profits. Low rates help this process by effectively reducing the value of money invested today think of the meager interest you get from your bank and increasing the importance of future returns.

"What we are seeing with Apple's rise and Facebook fall is a long-term story," says Frank Partnoy, a professor of finance and law at the University of San Diego, whose latest book, "Wait," extols the merits of thinking before acting. "People are looking at the two business models and saying: 'Apple is going to be around and Facebook might or might not be around.'"

If the thought of Facebook disappearing sounds preposterous, glance, if you will, at the scrap heap of once-hot technology companies from Netscape Communications Inc. to Myspace (formerly owned by the WSJ's parent company News Corp. (NWSA) ) or the army of severely wounded firms such as Nokia (NOK1V.HE) Corp., Hewlett-Packard (HPQ) Co. and Research In Motion (RIM.T) Ltd.

Apple could go the same way, but investors clearly don't think so, for reasons including a topnotch brand, a strong patent position (as Samsung Electronics (005930.SE) Co. just found out), its cash pile and its record of innovation and productivity. On average, Apple's employees generate 64% more revenues than Facebook's workers.

The second message concerns the companies' management teams, which are both led by rookie chief executive officers. The difference between Tim Cook and Mark Zuckerberg, however, is that the former is succeeding a legend while the latter has been hailed as a legend in the making.

So far, the market has been unequivocal: Since Steve Jobs' death, Apple's shares have risen 78%. Since Mr. Zuckerberg became CEO of a public company, Facebook's shares are down 49%.

Jeffrey Sonnenfeld, a management professor at Yale, believes the pre-IPO hype surrounding Facebook may have clouded its executives' judgement. "There was a grandiosity about the Facebook's management team that was problematic," he told me.

Mr. Sonnenfeld, an expert on how companies and executives can bounce back from serious setbacks, believes Mr. Zuckerberg shouldn't pull his hoodie over his eyes. "Going into denial mode would only get employees and investors more anxious," he said. Facebook declined to comment. Apple didn't respond to a request for comment.

The third issue is whether Apple's record value and Facebook's stock plunge should be seen as "sell" and "buy" signs, respectively, as per Warren Buffett's famous aphorism about being greedy when others are fearful and vice-versa.

I would point to two sets of numbers. First, once inflation is taken into account, Apple is smaller than Microsoft (MSFT) Corp., General Electric (GE) Co. and two other tech giants at their peaks. Optimists argue that is because Apple has room to expand, while the pessimists counter that it underlines fears of a slowdown in growth once the products developed in Mr. Jobs' "skunkworks" run out.

The other data point is the price/earnings ratio: Apple is trading at less than 13 times next year's estimated earnings, while Facebook is at around 30 times.

Despite its reputation for "irrational exuberance" and short-termism, the market appears remarkably cool and long-sighted in judging the prospects of two era-defining technology giants.

Francesco Guerrera is The Wall Street Journal's Money & Investing editor. Write to him at: currentaccount@wsj.com and follow him on Twitter: @guerreraf72.