Cruise operator stocks have suffered a brutal start to the year, as travelers postpone voyages over fears of the coronavirus.

Shares of Carnival Corp., Norwegian Cruise Line Holdings Ltd. and Royal Caribbean Cruises Ltd. were all down more than 46% in 2020 as of Friday’s close, erasing more than $37 billion in market capitalization in a matter of two months. The benchmark S&P 500 index was down 8% for the year as of Friday.

The...