New York (CNN Business) 1. Weak first quarter, but the rest of 2019 should be OK: The first quarter is over. Now we're about to find out just how bad it was for big American companies.

Earnings probably fell in the first three months of the year. But investors have largely looked past that. The Dow is up 13% so far in 2019 and is not far from its all-time high. The S&P 500 has surged 15% while the Nasdaq has skyrocketed nearly 20%.

The market is predicting that profit growth will return to near double-digit levels by the fourth quarter. So investors will need to pay close attention to what CEOs say about the remainder of 2019 in their earnings calls.

S&P 500 EPS growth forecasts Q1: -4.2%

Q2: 0.0%

Q3: +1.6%

Q4: +8.2% Source: FactSet Research

"Unless this quarter's earnings are much worse than consensus, the more important thing will be the guidance," said Cliff Corso, executive chairman of Insight North America.

Corso thinks that earnings for the full year could wind up increasing around 5% thanks to strength in the second half. That's not fantastic but it might be good enough to keep the market rally going -- albeit at a less explosive rate than previous years.