Boston realtor Mark Gough is predicting that once the city’s population hits 4 million, the city will soon sell its entire real estate market.

Gough told NBC Boston he believes that by the year 2020, the market for homes in Boston will be “the biggest market in the country.”

The Boston market is expected to grow at a much faster rate than the national average over the next decade.

And it has been growing faster than the population growth in other major cities.

Gough said he expects the city to surpass the U.S. as the nation’s top home-buyer market by the end of this decade.

As for what that might mean for the city of Boston, he said he thinks it will likely take years for it to recover from its housing market meltdown.

He also expects Boston will become one of the most expensive cities in the nation.

Grough said that would likely happen by 2025, with home prices hitting $2.5 million or more.

That would be the highest price ever for a home in Boston, according to a report from Realtor.com.