Mortgage rates fell in the first half of 2019, the opposite of what the experts had predicted at the beginning of the year. It is welcome news for home buyers, sellers and homeowners. NerdWallet has identified housing and mortgage trends to watch in the second half of 2019. Here are five of them:

Wanted: More homes for sale

More would-be buyers exist than homes for sale, giving sellers a stronger negotiating position. But, the balance of power is moving in the buyer's direction. More homes are available for sale now, so buyers have greater choice. That said, Freddie Mac estimates that in 2017, 370,000 fewer homes were built than needed to satisfy demand resulting from population growth.

Home prices will keep going up

In the first four months of 2019, the year-over-year price increases for resold homes were less than 4%. A year ago, prices were more than 4.5% higher. "Home price appreciation will slow down — the days of easy price gains are coming to an end — but prices will continue to rise," says Lawrence Yun, chief economist for the National Association of Realtors. Mortgage rates will remain low

Big lenders and the National Association of Realtors all predicted that mortgage rates would rise through 2019. Instead, mortgage rates have tumbled. The average APR for a 30-year fixed-rate mortgage fell to 4.09% by June 2019, according to NerdWallet.

The forecasters now predict that the 30-year fixed will remain steady through year's end, not changing by more than a couple of tenths of a percentage point.Affordability continues to be a concern

Mark Boud, chief economist for Metrostudy, calls the national housing market "top-heavy." Plenty of homes nationally are available for buyers who can afford to pay $800,000 or more. But buyers outnumber sellers of homes priced $400,000 or less. "We're still very short of supply in this lower price range," he says. More people could save by refinancing

Every time rates fall, there's an increase in the number of homeowners who could save money by refinancing.

Black Knight, a technology provider for the mortgage industry, estimates that 5.9 million homeowners could cut 0.75% or more from their mortgage interest rate by refinancing. Even if you bought your home recently, it's worth checking whether you should refinance.

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