What happened

Shares of Carnival Corporation (CCL -2.09%) are down 10.4% as of 11:20 a.m. EDT. Rival Royal Caribbean (RCL -0.39%) is off 10.6%, and travel reservations website Expedia (EXPE -1.39%) has sunk 6.3%.

I'll give you three guesses why -- but they'd better be coronavirus, coronavirus, and coronavirus.

Collage showing a cruise ship, a man in a face mask and a microbe

Image source: Getty Images.

So what

According to the latest data from the World Health Organization, global infections of COVID-19 topped 118,000 today, and the SARS-CoV-2 virus is now in 113 countries. Nearly 4,300 persons have died already, and the WHO is just inches away from declaring the worldwide outbreak a global pandemic.  

Yesterday, the Trump administration announced plans to suspend collection of payroll taxes to put more money in consumers' pockets so as to spur the economy to further growth, even as other countries, such as the U.K., announced emergency interest rate cuts with the same aim in mind.

The problem is, if this is the ameliorative path the White House decides to take, it doesn't really address the more immediate and specific concern afflicting investors in Carnival, Royal Caribbean, and Expedia: That it's travel industry stocks, specifically, that are bearing the brunt of this crisis, as discretionary consumers avoid spending on trips that could put them at greater risk of contracting the novel coronavirus.

Now what

Prior to the discussions of payroll tax cuts, the administration appeared to be focusing more intently on salvaging the travel industry in particular, with President Trump promising to work "very, very closely with the cruise industry [and the] airlines too ... helping them through this patch."  

Investors today may be worrying -- and may be right to worry -- that if the administration now gets distracted trying to save an entire forest of the economy, it may overlook the individual trees most at risk.

If you ask me, this is the worry that is sinking the stocks of Carnival, Royal Caribbean, and Expedia today.