British home prices will plummet if the United Kingdom votes to leave the European Union this week, billionaire investor Wilbur Ross said Tuesday.

The bulk of WL Ross & Co.’s business in the U.K. is in mortgage lending. Ross sees a home price collapse hitting older Britons particularly hard. Older people are skewing to vote to leave the EU in Thursday’s referendum, according to polls.

“The average house in the U.K. is about 250,000 pounds, and if it went down around 10 percent, which I think could very well happen, that would wipe out half the net worth of most of the older people who own their own homes,” he told CNBC’s “Squawk Box.”

According to Ross, a large majority of Britons over age 60 own their homes.

“I think they would be committing financial suicide,” he said.

Ross believes home prices would sink because foreign direct investment from Europe and exports to the continent would be interrupted. Further, a Brexit would be neither automatic nor clean, in his view.

The U.K. would have to mint new trade deals “by negotiating with the same bureaucrats in Brussels that they just thumbed their noses at. This would be a nightmare,” he said.

Those bureaucrats would be backed by EU countries, who want to show that exiting the union is no easy task, he said.