Shares of cruise line companies Royal Carribean (RCL) , Carnival Corp. (CCL) , and Norwegian Cruise Line Holdings (NCLH) have all sunk this week, and analysts at Wolfe Research gave investors insight as to why on Friday.

Primarily, weakness in China is the "biggest issue" and has dragged down the companies this week.

"Cruise stocks haven't traded well in the past two days following a channel check note, disclosure of more ship removals from China and possibly less ships going into China, a Skift news article speculating China could take more control over cruising, and sell-side downward estimate revisions," Wolfe noted.

The weakness in China is "vitally" crucial for the long-term outlook of cruise stocks. "If China yields don't come back in a meaningful way next year then we become increasingly concerned about the longer-term," the analysts added.

However, because China is only 5% of the companies' global supply and with robust trends globally, the firm sees little risk to near-terms performances.

"We believe the four biggest challenges right now are 1) the travel ban to South Korea, 2) too much supply, too quickly, 3) poor distribution, and 4) an extreme consumer preference for new tonnage," Wolfe argued.

The firm is maintaining its "Outperform" ratings on both Royal Carribean and Carnival Cruise Lines.

"We remain bullish, and we think that near-term demand trends will remain strong, and we expect cruise line stocks to continue to climb the wall of worry," Wolfe said.

More of What's Trending on TheStreet:

More from Stocks

Children's Place, Synchrony, Yeti and more: 'Mad Money' Lightning Round

Children's Place, Synchrony, Yeti and more: 'Mad Money' Lightning Round

Economist Perspective: Brexit Endgame in Sight?

Economist Perspective: Brexit Endgame in Sight?

Smaller Cap Stocks Could Make Great Stocking Stuffers Ahead of 2019

Smaller Cap Stocks Could Make Great Stocking Stuffers Ahead of 2019

Dow, S&P, Nasdaq Are All in Correction Territory Following Stock Selloff

Dow, S&P, Nasdaq Are All in Correction Territory Following Stock Selloff

Chart of the Day: The Cloud Kings Lost Their Crown in the Fourth Quarter

Chart of the Day: The Cloud Kings Lost Their Crown in the Fourth Quarter