As Britain anguishes over its effort to negotiate a deal to leave the European Union, one Israeli is swimming against the tide and is hoping to make a fortune off Brexit. He has bought up 1,200 apartments in London over the past half year.

Yakir Gabay bought the properties for about 500 million pounds ($630 million) through his company, Grand City Properties. The real estate was purchased in cash.

A source close to the company said the properties were all bought from developers and are middle-level real estate rather than high-end. Gabay was able to buy them at a discount of tens of percent thanks to the Brexit-induced slowdown in the London real estate market.

Although Gabay lives in the British capital, up to now he has been active mainly in Germany. Grand City, which specializes in residential real estate, owns 82,000 homes in Germany and is traded on the Frankfurt Stock Exchange at a market value of 3.3 billion euros ($3.8 billion).

But Brexit provided the firm with an opportunity to move into the London market, the source said. Since Brexit, London’s housing market has dropped by one to five percent, he explained. At the same time, the pound has fallen 20 percent. As a result, many developers have stopped building new projects, and they have to sell under pressure.

That has enabled Gabay's company to sign deals at discounts of up to 30 percent. But that is only because the company is paying in cash and is solving the contractor’s problems with the banks, the source said.

It you look at the long term, he added, Brexit provided an opportunity to get into the market in Europe’s strongest city. That opportunity, he said, had last arisen in 2009.

There’s a risk that the housing market might collapse following Brexit, the source acknowledged, but there is also potential. And if there are problems, the rental market might actually benefit. The company isn’t buying to sell, he said. It's in it for the long term.

Buying at a discount also provide a certain level of protection, he added. And to limit the risk, Grand City decided to restrict its investments in London to no more than 10 percent of its asset portfolio.

While Brexit has caused a housing slowdown throughout Britain, it has been particularly marked in London. The Guardian newspaper reported this week that overall, British housing prices fell 1.7 percent in November, the sharpest drop since 2012, citing data from the real estate website Rightmove. The fall was especially steep in Britain’s wealthiest cities, including London.

Grand City is owned by another Gabay company, Aroundtown. That company trades in Frankfurt at a market capitalization of 8.4 billion euros.