The exponential spread of the coronavirus is upending the travel industry with cruise operators being hit particularly hard.

On Thursday, cruise stocks fell following the news that roughly 6,000 passengers were being held on a Costa Smeralda cruise ship amid fears that a person onboard potentially had the virus that originated in Wuhan, China.

“By our math, every lost voyage is $3 to $4 million of revenue, and about $0.02 of earnings,” James Hardiman, the managing director of equity research for Wedbush Securities, told Yahoo Finance’s On The Move on Tuesday.

Royal Caribbean International (RCL), the world’s largest cruise operator, canceled cruises from Shanghai while Carnival (CCL) canceled several of its scheduled trips in the region. Royal Caribbean stock was down 3.8% as of 1:30 p.m. EST on Thursday, while Carnival was down over 4.6%.

The cancellations will have a negative impact on earnings, according to Hardiman.

“I think with every passing day it is becoming a — it's creating a materially negative impact on the earnings at some of these cruise companies,” he said.

Hardiman, who focuses on travel companies, said hope rests with stabilization of the virus. But, he adds, “In the absence of that, I think they're going to have to be extra conservative in terms of how they guide 2020.”

Nobody in the travel business is spared as people around the world curtail their travel, Hardiman noted. United Airlines (UAL), British Airways, and Finnair have suspended some flights to China, and other airlines are offering refunds for those who have booked travel.

How does coronavirus compare with SARS?

It’s difficult to assess the extent of harm caused by coronavirus, but analysts often cite the severe acute respiratory syndrome (SARS) outbreak of 2002-2003 as they try to make sense of how coronavirus will affect the markets.

SARS cost the global economy more than $40 billion, but Hardiman cautions that it’s not an accurate comparison, in part because companies today have far greater exposure to China.

“The only challenge with SARS from a stock perspective is the idea that back then, you know, early 2000s, most of these companies, whether it's the cruise names or the online travel names that we follow, neither of them had anywhere near the exposure that they have today with respect to China and broader Asia,” he said.

However, it may still be too early to determine the outcome of the virus. “I think that the impact is going to be widespread,” Hardiman said. “You know, a year from now, we're going to look back upon this and at some point there's going to be a buying opportunity. But as we sit here in the midst of it, it's hard to say when and where that is exactly.”