And they're off. Alcoa kicked off the first quarter earnings parade on Monday, reporting an increase in quarterly profit but revenue that fell short. It will be followed by major banks JPMorgan Chase and Wells Fargo this Friday and the rest of the S&P 500 over the next three weeks.
Alcoa is a good proxy on the demand side of the story for the global economy, particularly China, where an economic slowdown has been talked about, but not without debate—China has been growing consistently year after year for decades.
Alcoa CEO Klaus Kleinfeld was just in China and said every company he met with had expectations of 7-8 percent growth. He told CNBC's "Closing Bell" he is optimistic about aerospace, building and construction boosting aluminum sales this quarter.
(Read More: Alcoa Kicks Off Earnings Season With Mixed Report)
Overall, though, most sources are expecting a slow earnings period. S&P Capital IQ said to look for earnings growth for the S&P 500 of just six-tenths of a percent. It expects revenue growth of just 4 percent, which will be down from 4.7 percent a year earlier.
These are slow numbers relative to a stock market that is up 10 percent in 2013. That in and of itself is not terrible. The real question is how much of this is priced into the market and whether a slow earnings period be the excuse some investors have been looking for to sell into this historic rally.
I continue to expect a buy-on-the-dip mentality for the stock market despite the fact that I think earnings will not be flat at best. Yes, investors will probably sell sooner and think later when this slow pace of earnings growth materializes.
However, with the Federal Reserve stimulus in place and not expected to go away anytime soon, any selloff will be met with buyers. I continue to hear of deep-pocketed investors globally, ready to buy on any dips as they search for yield. With the Fed keeping rates where they are, there are simply very few alternatives to owning U.S. stocks. However, I have been getting worried recently with so many talking heads from the Fed out publicly defending quantitative easing. It is not normal.
Just like investors are searching for yield, CEOs and business managers are searching for growth. Even with the slow performance, we are expecting some areas to outperform.
The best sectors for the first quarter will likely be telecom, which has an expected earnings growth of 9.4 percent, and consumer discretionary, with an expected growth of 8.2 percent. Media stocks have also been trading well, indicating an expected outperformance in the sector. Caterpillar is seen as a real weak spot because of a slow global growth story. Profits are expected to fall 40 percent.
The expectations do indicate a comeback by year's end. In fact, after an anemic first quarter, earnings are expected to rise 7 percent in the second quarter, 9.1 percent in the third quarter and 12.8 percent in the fourth quarter.
Overall, earnings growth for 2013 is seen as coming in at 7.5 percent for the year, according to S&P Capital IQ estimates from Wall Street analysts. But the economic underpinnings—machinery, airfreight and logistics—are lagging, as we saw with the big misses from FedEx and Caterpillar.
(Read More: FedEx Earnings Fall Short on International Weakness)
I have said before and I still believe, investors should not fight the Fed. I still expect selloffs to be met with that buy-on-the-dip mentality, but a weak earnings story and a pullback in economic growth could be that excuse so many are looking for to trigger a bigger selloff, which will clear the decks for those buyers to come back in down the road.
Technicians will tell you one of the best things about this stock market rally of 2013, and why they think it will continue, is that so many people don't believe it and continue to question when the next selloff will come.
That is a positive for a longer term secular bull market but still opens the door for some choppiness and selling in between, before those buyers come back in.
Bottom line, there may be some opportunities to get in on this rally if you have missed it.
—By CNBC's Maria Bartiromo; Follow her on Twitter: @MariaBartiromo