Barclays said the strength in earnings from companies with a focus on the domestic economy was linked to signs of a pick-up in euro zone growth, which has received a boost from European Central Bank monetary stimulus.
Concrete signs of this pick-up could be seen Wednesday when first-quarter gross domestic product (GDP) numbers for the euro zone are due out with analysts polled by Reuters forecasting a 0.5 percent increase from the previous quarter.
Read More Euro zone set to report solid growth, for a change
That would put euro zone GDP ahead of the U.K., which grew 0.3 percent quarter-on-quarter in the first three months of the year and has been consistently leading Europe's big economies. The U.S. economy, the world's biggest, grew an annual rate of just 0.2 percent in the first quarter.
"There is a tendency to think we have come too far, too quickly with the rally in European equity markets," Michael Hewson, chief market analyst at CMC Markets, told CNBC. "We now want to see this confirmed in Wednesday's GDP numbers."
After years of lagging their U.S. peers, some analysts expect euro zone companies to post double-digit earnings growth this year thanks to a weaker euro, a sharp drop in oil prices and lower funding costs.
The euro has tumbled more than 20 percent against the dollar in the past year, while oil prices have fallen roughly 32 percent in the past year – delivering a powerful boost to consumers and firms.
Roughly three-quarters of the companies of the broad Euro STOXX 600 have reported earnings so far and according to Barclays, 76 percent of these firms have beaten or are in line with estimates on sales, while 67 percent have beaten or are in line on EPS.
Read MoreDisappointing earnings season? Not in Europe