Amazon's competition with big retail should not have market observers that worried the tech giant is going to "take over everything," an economist said Thursday.

"What will likely stop Amazon in terms of market perception will be reality," Daniel Lacalle, chief economist at Tressis Gestion, told CNBC. "There's this view in the market that Amazon is going to take over everything. And there are limits."

Amazon took up 44 percent of all U.S. online retail sales in 2017 — and 4 percent of America's total retail sales — according to data released by One Click Retail last month.

Its retail market share was seen to be a main factor causing a decline in Walmart's gross margins when the corporation posted earnings Tuesday.

But Lacalle said market observers should not expect Amazon to dominate the globe.

"I think that Amazon is also delivering, but what you cannot expect is this sort of global takeover, that Amazon will destroy every single sector because people are getting smart and I think that that is a positive," he said.

Amazon has aggressively expanded its business to target sectors including finance and health. It was one of three companies, the others being J. P. Morgan and Berkshire Hathaway, to announce in January the launch of a new firm that will look to simplify U.S. health care with technology. And it quietly launched an exclusive range of over-the-counter health products, made by pharmaceuticals manufacturer Perrigo.

Amazon has also made a push into finance with its own lending service for merchants, and last week it was revealed that the tech giant had partnered with Bank of America to provide loans for that service.

Shares of Amazon hits an all-time high on Wednesday, reaching $1,500 for the first time. Its stock has rocketed more than 70 percent in the last 12 months.

The firm's fourth quarter earnings led to a slew of upgrades from analysts earlier this month.

Amazon's stock was trading almost half a percent higher in U.S. premarket trade at 7:19 a.m. ET.