NEW YORK (CNN/Money) - Earnings season is about to kick off, and U.S. companies will likely post the best quarterly profit growth they've seen in over a decade.

Wall Street, apparently, hasn't fully factored in all the good news yet.

Signs abound that business picked up substantially as 2003 came to a close, but analysts' forecast of fourth-quarter S&P 500 earnings growth of 22.3 percent is little changed from where it was back in April. Moreover, far fewer companies have warned of results falling short of expectations than is typically the case; normally that means results will trump forecasts by a long shot.

First Call strategist Joe Cooper reckons that means actual S&P earnings will be 26 percent ahead of last year's fourth quarter. You have to go all the way back to the third quarter of 1993 to top that.

The question is whether investors -- and never mind the analysts -- have figured out how good things are going to be.

The 1993 experience is instructive: Despite the massive strength of third-quarter earnings, the market made only middling gains -- perhaps because investors understood that profit growth was as good as it was going to be, and that the Fed was about to start tightening the screws.

Could we be in for a repeat?

Companies in this report: Intel; Yahoo!; General Electric.

Chip stocks enjoyed incredible gains in 2003. The Philadelphia Semiconductor Index surged 76 percent. If investors are hoping for a similarly strong 2004, then industry leader Intel will need to report fairly solid fourth quarter results and give bullish guidance for the year.

For Intel (INTC: Research, Estimates) and other chip companies, meeting estimates is no longer merely good enough. In fact, the company's stock took a hit in early December after Intel simply raised the low end of its sales forecast. Shares tumbled 10 percent in the three days following that report.

The stock has recovered since then amid hopes that strong consumer PC sales in the fourth quarter will continue throughout 2004. But investors will want to hear confirmation of this in Intel's conference call in order to justify more gains ahead.

Wall Street will also be closely keeping an eye on what Intel says about the corporate spending market. Many businesses have still been hesitant to upgrade old machines and Wall Street is hoping that the corporate IT spending slump will finally come to an end this year.

Why it matters: If Intel issues strong guidance for the first quarter that could lift all tech stocks, not just the chip sector. Good news from Intel could be interpreted as a plus for other large companies in the PC food chain, including Microsoft, IBM, Dell and Hewlett-Packard.

The company is also expected to give a first look at what its capital spending budget is for the year. And since Intel is a big customer of semiconductor equipment stocks firms such as Applied Materials and Novellus Systems, an increase in Intel's capital spending plans from 2003 would be a very welcome sign for the chip equipment sector.

First Call forecast: 25 cents a share versus 16 cents a year earlier.

It's funny how the Internet has evolved. In the late '90s, online advertising was all the rage as everyone talked about "monetizing eyeballs" and "banner click-through rates".

But once the Nasdaq and dot-coms in particular imploded, the words "online advertising" became dirtier than anything George Carlin wasn't allowed to say on TV.

Now Internet advertising is white hot again, thanks to so-called sponsored searches, which allow companies to pay a premium for ads tied to particular keywords. Yahoo! (YHOO: Research, Estimates) has been benefiting from this trend and Wall Street will be looking for more clues about the health of the online ad market in its conference call.

Time Warner chairman Dick Parsons hinted in a speech this week that the online ad market was improving for the company's AOL unit. (Time Warner is also the parent of CNN/Money). And if this is a truly broad-based recovery, then no company seems prepared to benefit more than Yahoo!, which despite some diversification efforts, still generates nearly 70 percent of its total sales from advertising.

But this could be a more challenging year for Yahoo! The company is expected to drop sponsored-search partner (and everybody's favorite soon-to-be hot IPO) Google in favor of search technology it has acquired.

Yahoo! spent about $2 billion in the past few years to buy Inktomi and Overture Services so could it afford to cut ties with Google. Wall Street's about to find out if the strategy worked. With the stock trading at 88 times 2004 earnings estimates, Yahoo! can ill afford even the slightest of missteps.

Why it matters: Shares of Yahoo! doubled last year on hopes that the dot-com bloodbath was at last over. Companies that survived were now perceived as legitimate technology bellwethers and in the case of Yahoo!, a true media titan as well.

So if Yahoo! is really seeing an uptick in ad spending, that's probably going to paint a better picture of how well diversified media giants like Time Warner, Walt Disney, News Corp and Viacom might do this year, as opposed to what lies ahead for other more e-commerce focused Net stocks like Amazon.com and eBay.

First Call forecast: 10 cents a share versus 8 cents a year earlier.

General Electric (GE: Research, Estimates) may not command the same sort of rapture from investors as it did in the Jack Welch years, but it has allayed many of the worries that they had going into 2003.

It's cut back what was seen as an over reliance on short term debt for its funding needs and it has upped the level of disclosure in regulatory filings -- particularly in the instance of its once famously opaque GE Capital division.

GE may be off the mat, but it is not off the ropes. Its aircraft engine division is still suffering from the struggles of the airline industry and its big power turbine division is also having a tough time of it. With the falloff in mortgage activity, its consumer business will not be the same sort of driver its been in the past. Back in November, CEO Jeffrey Immelt said earnings probably wouldn't grow by more than 6 percent in 2004 and could potentially decline. It's not until 2005 that GE will get back to double-digit earnings growth, said Immelt.

There's potential that GE's prospects will be better over the next year than Immelt indicated. The economy grew much more rapidly in the fourth quarter than most economists thought it would, and the first quarter has shaped up well. Potentially, results at GE's many economically sensitive businesses will be far better than analysts expect.

YOUR E-MAIL ALERTS Follow the news that matters to you. Create your own alert to be notified on topics you're interested in. Or, visit Popular Alerts for suggestions. Manage alerts | What is this?

Why it matters: General Electric may not be the same bellwether for business in the United States as in the past, but it is still the world's largest company by market capitalization and how it performs still says something about the economy. If it tops analysts' estimates or, more important, raises its guidance for the year it would indicate that we're far closer to full-blown recovery than most Wall Streeters think

First Call forecast: 45 cents a share, versus 31 cents a year ago