Why Apple's Plunge Has Been Positive for Stocks

Apple CEO Tim Cook
Getty Images
Apple CEO Tim Cook

In at least a roundabout way, Apple's precipitous and rapid fall has been the stock market's gain.

Though few if any stocks on the Standard & Poor's 500 get attention comparable to the technology behemoth, its 44 percent plunge off its Sept. 19, 2012 historic high has coincided with an 8 percent surge on the broad market index.

So what happened to that $291 billion in market capitalization that Apple lost?

A bevy of other stocks have been there to happily pick up the slack.

(Read More: Nasdaq Could Rebound to 4,100: Charts)

"Apple is just another tech stock," said Mitchell Goldberg, president at ClientFirst Strategy. "Apple stock has become a source of funding for the rest of the market. The lower Apple went, the higher the rest of the market went."

Indeed, while Apple slid other companies — competitors or not — gained. It's the opinion of Goldberg and others in the market that the money used from Apple share selling helped pave the way.

The stock's changing role as market barometer comes as the company prepares to release first-quarter earnings that, for anyone else, would be sparkling but for Apple may be pedestrian or worse.

(Read More: Here's What Pros Say May Turn Apple Around)

There is no 1-to-1 comparison that shows exactly where Apple dollars went, but a broad swath of firms in the tech space continued to chart upward as Apple slid.

The Nasdaq stock index, considered a proxy for the state of technology, has risen just 3 percent during the period. Apple was nearly 20 percent of the total Nasdaq market cap at its apex — considered by some traders as a pivotal level that triggers selling — and is down to only about 11 percent now.

But in the meantime, individual names, including beleaguered companies such as Yahoo (55 percent higher) and Hewlett-Packward (up 12 percent), have soared.

(Read More: Netflix's Focus on Targeted, Premium Content Works)

At the same time, the S&P 500's market cap has surged $600 billion to $13.9 trillion.

Apple, though, has lost its lofty perch atop the S&P 500, ceding its role as the largest percentage of market cap to ExxonMobil.

(Read More: What Apple Bears May Be Missing)

"Apple has handed over the baton," said one trader long on Apple and unwilling to be quoted directly. "You could be watching an Apple into Microsoft and Google trade. It's gone from the most over-owned stock in mutual funds to somewhere in the middle of the pack."

Nevertheless, it's also paved the way for other stocks, many of a defensive nature, to move to the front of the pack.

So while all of Wall Street and Silicon Valley will be watching Apple's results later Tuesday, making broad-based decisions - or Apple-specific ones, for that matter - off the profit report may not be wise.

"Forget about quarterly numbers," said Nadav Baum, executive vice president at BPU Investment Management. "Let's talk about the business. If the business is great it will be a good investment for those that stay in for the long haul."

As for the near term, though, Baum advises not betting the entire portfolio on one company.

"Diversify," he said. "You buy great stocks, you buy great companies and you don't put everything in one stock. Over the time the growth of the stock market will do well for you if you continue to buy high-quality, great businesses."

-By CNBC.com's Jeff Cox. Follow him on Twitter @JeffCoxCNBCcom.